I don't think there is anything to fear from reputed agencies themselves, they don't care of stealing your goodies, they make more money keeping there reputation and your business. When it comes to the girls, well there can always be a bad apple in a good bag... you never know what SHE can do on her side with her friends or whatever. If you have lots of valuable objects/money/jewels or such, you probably can pay the hotel/motel room, maybe better go with this? For a regular block with a video game consol and a 5 years old lap top... i wouldn't fear too much of being targeted... Unless she clearly knows your schedule, and when to hit... she would probably get more of stealing from another random place anyway...
You can always also play a factor of trust with her... if she become a regular, you feel she is a good person, then let her come home eventually.
Personally i don't have much valuables myself, but i would never trust a girl from the old newspaper agencies in sherbrooke(dunno if there still operating since newspaper adds have disapeared) to come to my place... but would i live in MTL, i would certainly trust the regular agencies i used.
Thing is the human mind not always make sense, you see people killing and getting a life sentence for a mere 500$ in a robbery turned murder sometimes... they shit there whole life for 500 bucks? This is so stupid and aberant... they could make this in 2 weeks of work... even at minimal wages. So its always hard to trust people...you never know how fucked up there mind can be...