Any laptops are fine I bought a used laptop in 2009 which is 4yrs but it was probably 3 or 4yrs used then so 8yrs. I am using it right now. Absolutely fine, I even have a older version of Photoshop. Checked a review was done in 2007 so at least 6yrs old. Mine had Wifi G so that is fine too.
Just remeber that to store photo's online you may be taking a while, esp if you are on travel, using the free Wifi internet, quite slow. With today's high megapixel files. At a guess of a speed of 0.5Mbps, for upload that is 0.5/8 = 0.0625MB/sec. If the pictures are 5MB each, each photo takes 80 seconds. 100 pictures takes 133 minutes. At home you might get a 1Mbps upload so double that and you may not get much higher unless you have fiber optic etc. or at least if you got VDSL instead of the standard ADSL.
With normal ADSL or I guess similarly with free wifi, you would be lucky to match ADSL with it.... Anyway ADSL where I am at home here in NZ generally have a download of up to 20Mbps or many get just 8Mbps depends how close you are to the telephone server box beside the road so quite fast to download stuff like emails, webpages, movies etc ..... but the upload speed to send other people stuff is only 1Mbps.
Some people just take a USB stick and copy them there as well for a 2nd back up after hte laptop.....
Edit - if it is for travel what about something like 200GBP at least here in NZ we can get a 10" Samsung tablet, could be ok for your kid(s) on the plane and easier to transport, they might enjoy touching and pointing on the screen too.... Some have Wifi so you can use the internet that way ..... don't need the expensive ones with simcard. Just check if they have usb ports b/c not all I think do that ........
Edited by: Rayonline