Hi, I'm Ashik. Welcome to JustAnswer. I'm reviewing your question now, and will post back with your reply ASAP
It is indeed possible to recover deleted files from memory cards. The are many recovery applications out there that can recover deleted files. Are you using an Apple Mac or Windows PC computer ?
Remove the memory card from the iPad and make sure you don't take any pictures on the card until you get all the deleted photos recovered. The more you use the card, the less the chance of recovering.
To recover deleted files, you need to use your computer. You will not be able to do this from your iPad. Plug in the memory card to your computer. If you don't have a memory card reader there, then you need to buy one. You can buy memory card reader from any local electronic stores. See here --> https://www.amazon.com/Sabrent-SuperSpeed-Windows-Certain-Android/dp/B018X9UN1U/ref=sr_1_1?s=pc&ie=UTF8&qid=1467689841&sr=1-1-spons&keywords=memory+card+reader&psc=1
After connecting the card to your computer, you need to download Memory Card Recovery applications to use them to recover photos. Following are some applications (try the version of recovery applications before buying them)
EaseUS Data Recovery --> http://www.easeus.com/resource/memory-card-format-recovery.htm
Card Recovery : https://www.cardrecovery.com/
7 Data Recovery : http://7datarecovery.com/sd-memory-card-recovery/
(Note : Make sure you check the Recently deleted folder of your iPad in Photos app and the photos are not there. If they are there, you can restore them without using these recovery applications)
If you have any questions or if you have any difficulty on following the steps above, please let me know and I will continue to help you