Resetting iPad To Factory Setting

Hello

I want to reset an iPad Air that I have back to factory settings but I'm not sure what problems this may create for the previous owner of it.

The iPad was going to be thrown out by a sibling of mine.

I asked them if they had it wiped before thinking about throwing it out and they didn't and they weren't sure how to do that so, I took it thinking I could do it.

It's a first generation iPad.

I charged it back up and the iPad seems to work perfectly fine so, I plan to use it.

Here's the issue.

The previous owner's Apple ID is still being used on the iPad.

Anything I've read so far indicates that in order to sign out of Apple ID, that persons Apple ID password needs to be used.

I'm not going to ask my sibling for their Apple ID password and we live quite a distance apart for either them to come to me or me to them just to have a password entered.

So, if I can reset the iPad to factory settings without the previous owner signing out of their Apple ID on it, will that cause any issues with their Apple ID on their iPhone?

They won't loose their contact list, pictures, etc that they have on their phone?

This won't affect if they are using the cloud feature on their phone?

I'm assuming resetting one device shouldn't effect the other but, not 100% sure.