The art T's emails are very confusing for sure. I would feel the same as you. You've been very clear and upfront but hers are full of mixed messages. She definitely doesn't sound keen but is for whatever reason reluctant to just wish you well. I'm wondering whether she's reluctant to commit but thinks she may be persuaded once she's met you, so doesn't want to say a firm no? She might also be thinking that once you've met her you might commit to her and her alone and doesn't want to pass up that opportunity. She's running a business after all.

In your situation I might wait until my T comes back and discuss it with her. Or I might give into curiosity and meet the art T and see what she's like.

Another option is emailing her again and saying how confused you are and ask whether she's truly open to what you're looking for. I know this might be difficult though given how her responses have gone so far and might mean starting any relationship with her on a bad note.

I hope it works out whether you decide.