We currently let them use our iPads. Almost 4 year old DD gets iPad time on the weekends when DD2 naps. Both get iPad time for long-ish car trips.

DD1 has my well functioning iPad
DD2 has DH's old iPad that's pretttty slow but works to just put on a show

My main problem is memory. I have to go in and rotate downloaded content b/c there isn't enough room and also Amazon has a max # of downloads.

Would getting them Kindle Fire w/ the most memory (and since it's also expandable with SD card) fix all of this? Getting new iPads is definitely not an option.

I know us and the girls are used to and probably prefer iPad usability, but getting them new devices w/ much more room, especially if we travel, is very tempting as well.