IPAD Apple ID

I have two IPADs (an old one and a new one). My seven yearold son is all up to speed on the new one. He has an apple ID and has set up all his apps and docs. The old Ipad is currently signed in under my apple ID but i now want to log out of my apple ID and allow my mother to login in with her Apple ID and use this device for facetime, crossword, and apps that she uses. She already has an Iphone and is set up!

Can you walk me through the process of logging out of my apple id and logging in with her Apple ID?

I believe it's best to have her use the old Ipad under her own ID going forward to avoid any overlapping of apps etc and confusion. Correct?

Thank you,

Jeremiah