this sounds to me like a real annoying situation.

in the first place, how do you want to deal with this situation? especially she is invading your weekends.

just wondering she is asking you for directions on how to do the documents, or in the process of asking that you are doing it for her? as in after she asks so many stuff that you ended up giving her the end product? because i have known people who 'pretend' to ask and then don't know what happen in between that the request 'you do la' occurs.

i'm seeing this situation as no boundary, and it's also hard for you to set a boundary without hurting some professional working relationship. just wondering is your department dealing with your working previous working place's department? if not, boundary setting can be a little easier.

did your former boss ask you in any way how to complete your stuff before you leave?

it looks like she held you hostage. that's not good.

sounds like a good advise. otherwise, you might want to inform your former boss too.