Yeah, the other thing you could do is just say "oh, it's fine" and then change the subject. Sometimes people from that generation don't understand the boundary (in my experience) and if you just keep changing the subject and give her no information, she'll figure out that it's not a topic of discussion.

I don't think you need to go into detail. And I don't think you need to justify anything to her. You could always figure out a line that works for you. I have had to do this a lot, it's not a lie, just the response I give to questions that come up often. Like when people ask what my disability is, and I just say, you know that's personal and I don't like talking about it. And they leave it alone.

So you could always figure out what your go-to response will be. Honestly, I would just keep changing the subject and if she won't drop it say you don't want to discuss it. If she won't stop, you walk away. You don't owe anyone any discussion or justification of anything.

One "line" you could use is that the job search is fine, you're considering different opportunities, and right now focusing on volunteering to help you narrow down your interests. And then leave it at that. If you actually wanted to have an easy answer to get you out of it.