only just came across this post...how is it going now?

i have to say that i am a little concerned by this one. and like Nae my feeling is that this is a different person. i guess my main concern is from what you have mentioned with your feeling of uneasiness and also, i never really like the ones that watch. honest, i do think it's rude and usually let them know: not in a 'get your freak on and be angry' way, but just a common courtesy 'we all share this space so deal with it' way ITMS. had this one in a house our friends lived in in Fiji. the house over time got a 'heavy' feeling and i would feel rather constrained when visiting as though we were intruding. turns out the person was unusually attached to my friend and found others that were around to be a hassle and interference (this included her DH and DD). Increasingly she (was a young child of about 12ish years i could gauge) became a little more confident in dealing out uncomfortable feelings...and this DID coincide with my friend and her family deciding to move out. so maybe the increase in activity from your visitor has a correlation with plans for you guys to move? maybe this person has been there the whole time (i'm figuring that they have a connection to your DD?) and is slightly concerned about said moves. either way, i think they are overstepping the boundaries (no pun intended ).

keep your ears and eyes out and trust yourself (and your furbabies!), if it does get too uncomfortable at times, i would take yourself and DD out for a bit (also it might be worth checking out some strategies for closing off DD from the visitor): i think the closing of the gates and doors is going too far in its disapproval (of whatever it is unhappy about ITMS).

P.S. it's a good thing that your DH is able to get the visitor to leave, maybe channel some of his energy through the house for when he is not there?