Hi, I'm spending 3 nights in Singapore in May with my mother, who is 73 and had a small stroke last year. We are on a budget, so ideally would like to stick to around the $100singapore. I don't want Mum to have to walk too far in the heat, so it needs to be fairly near to an MRT or good bus service. It needs air-con for the same reason and somewhere like the red light district would not be suitable! We don't need special facilities or anything, I just want my mother to have a good nights sleep in a clean quiet bed and be able to be out of the heat in the room and not going too far to venture out. Too much to ask? I've tried the new 7th storey, but they are booked up. I've spent HOURS looking at reviews and it seems hard to find somewhere decent for not too much money. Any suggestions very gratefully received.

The Lion City Hotel, SGD$130 or between that and SGD$200 anyway.
Note that the cheaper hotels can also be the "ahem" hotels, so don't go for something too low.
SGD$48 for an own bedded room in the Inn Crowd, in Little India, close to the MRT, but that has got a set of steep staircase.
I would say you have to up your budget.
Singapore taxis are very good, and its very very unlikely you will be scammed as what would happen in say, Malaysia.
All hotels in Singapore will be aircond, some of the hostels will be fan cooled, but all hotels will be aircond, its the standard.
I know you do say you are on a budget, but how high can you go?
If you are happy to be away from the MRT, but on a taxi route, try the Miramar Hotel, close to Chinatown, but not on the MRT though.
SGD$250 if booked online, so you can see, the closer to the city you go, the more $$$ it will be. Ouch, yes, ouchy $$$$ expensive.
Fragrance & Hotel 81 are cheap, yes, but they are also the 2 hour type of hotels, if you get my drift. Of course, other hotels will also have ahem going on, but Fragrance & Hotel 81 are the regulars.

If you go to Hotel Club, www.hotelclub.com.au and type in Singapore, and pick 3 to 4 star, you will see the hotels listed, with prices.
The lowest ones are the Fragrance & Hotel 81, but after that, there are the others.
There are also review pages, from people who have stayed there in those hotels.
I can only give the names of 2, which are outside your budget, too $$$$$$$$, but they are worth their weight in gold.
Hotel Peninsula Excelsior, near St Andrews Cathedral in the city centre.
Holiday Inn on the Park, Singapore, near Orchard Road.
Ducted aircond, included bathroom, have room service & minibar, NOTE: lots of hotels are the type where the shower is inside the long bath, so if your mum can't lift over the long bath sides, its going to be a problem.
Something to consider too, is if you really want something good, and are willing to save a lot for it, is to go for the serviced apartment type of places, not cheap, but better still in the sense that you can prepare your own food, and can cook your own meals ot her diet specifications.
While food in Singapore's hawkers centres are good, they tend to be fried, and tend to be not very healthy long term, cooked in oil.
For eg, fried chicken rice will have quite an amount of oil, both in the rice and in the chicken broth.
Curries, while might not contain oil, will have ghee in it.
If you get a serviced apartment, you could boil up say, healthy vegetables, or stead something in the microwave oven.
I guess it all depends on if your mum is on a diet or not, and how mobile she is.

Whenever we go to Singapore, which is often, we stay at www.1bnbsingapore.com/. It's about a 10 minute walk from the Outram MRT and less than a 5 minute walk from a major bus stop and very close to a nice neighborhood with lots of renovated Chinese shophouses. The neighborhood is very safe, all rooms have air-con, and the view from the 25th floor is fantastic. Doubles are S$80 - S$100 and that includes a full, hot breakfast. Very clean, suitable for older people and children. Check out their website - if you like it, book early because they tend to be full every night. It's more of a homestay than a hotel, which is one thing we like about it - very quiet and comfortable. It's practically across the street from the Tanjong Pagar railway station - a five minute walk. Considering how prices have gone in Singapore lately, we think that it's one of the last bargains - and it's definitely not a hostel. Enjoy!

New 7th Storey Hotel: http://www.nsshotel.com
It is really clean. All rooms have A/C and cable TV. Hot water, etc etc. Elevator (important for your mum!) Very safe.
Perfect location -- walking distance to many neighborhoods and just 1 block from the Bugis subway stop.

Oops -- I just noticed in your posting that you already tried the NSS Hotel and they were booked. Good luck!

Best bet is the Hotel 81 group. Yeah, I hear some Singaporeans sniggering because these are somewhat stigmatized as 'Love Hotels'.
Fact is they provide good clean facilities, cable TV, air-con, toothbrush and complimentary snacks/coffee etc. at around S$80 a night.
Often young couples take advantage of them because in a culture where most unmarried folk live at home and privacy is at a premium, they offer a service which is great value.
There's one on New Bridge Road, Chinatown that is a converted colonial building and the location is fantastic.
Check it out.
Someone mentioned Lion City (Katong)- it's a 3 star dump pretending to be a classy hotel at almost twice the price.
Good luck.
PS My mum is 79 and she was extremely happy in the Betel Box backpackers on Joo Chiat Rd. (Double S$50)
The Vietnamese street walkers outside adopted her as 'Mae', bought her food and beer and gave her lots of cuddles and kisses... She was a star.
(But she's a total groover, your mum would be fine at any of the 81's.)

Thank you so much everyone for the really thoughtful replies. I've emailed a couple of places recommended above and fingers crossed I will be able to get somewhere at one of those. As for the budget - if we have to pay more then we will. I want Mum to have a good time as it's a big trip for her, but having said that - I'm helping Mum out a little financially over the next couple of months while she is away and money only goes so far. As long as the room is quiet, clean and cool and the location reasonable for her then that's fine for us. My mother would be mortified to be at a hotel which rented rooms for a few hours at a time. We don't need luxury. If anyone is familiar with travelodge in the UK - something like that is fine. Thanks so much again. I am really delighted that people have gone to so much trouble and thought to offer great suggestions.

Hi, try YWCA Fort Canning Lodget Singapore. The location is ideal and I belive the room rates is within your means.
reservations@ywcafclodge.org.sg
http://www.ywcafclodge.org.sg