So, for context i (M23) am a professional dog trainer, and one of my students (F43) always vibed with me, since she was assigned to me. She said she only wanted to have classes with me, and latter started leaving the dog with me for days, the relationship evolved to something less professional, nothing physical or whatever, just good vibes, and funny light moments, but my colleagues always said she had a thing for me, but i was in a relationship, that ended some time now. And now she became a bit for straight foward, calling me names like "babe" "sweety" stuff like that. Anyways, she has made conversation about knowing me better, what i do beside dog training, etc.

Once we went on a walk with the dog, so i could teach her some things, since she leaves the dog a lot with me for me to prepare him. And i proposed we go on a walk again this weekend, and since my birthday was this week i said "we should do the birthday lunch, i'll bring the cake ;)" she said "Good plan, lets do it". Nothing much yet.

Now that some context is established my question is: Where to i go from now, we have lunch, and im like lost on how to escalate things, since i've never done this with someone this older, only girls my age or slightly younger. And besides this we have a professional relationship, so if someone could help me with some insights i would appreciate it!