this one is a bit more complicated to explain. There is a walk-through document for version 2.10 attached to the original post. You might want to have a look into that.
I cannot remember any specific difficulty with that. The first time you take her out in a cutscene is when you have to talk to the pet owner in order to gather information on Seraphine.
After that, once you have enrolled TRis into the pet class and she has done it she can go on normal pet walks as a favour
It's weird, cause for some reason I just can't take her out on the pet walk to the pet owner. I've got the quest to get his trust, the quest saus it requires T'Ris' EXH to be a 12, which I have, but the MC is just saying "I can't think of a suitable public favor in this location" when I ask for a public favor from her.
If you feel that this is a issue in the software and you know how to locate a save game file, you can drop it on some sharing service and send me the link and I can have a look into it.
Maybe it is some edge case that has been overlooked so far...
If you are a patron on Patreon or subscribe star you can also drop this file into the Help channel on Discord