Hey Des...........sounds like she is fear peeing or submission peeing. She is such a tiny little gal, we all must look "HUGE" to her and that's scarey enough! LOL But does she pee when someone approaches if "YOU" are holding her not in the carrier???? That may be the way to socialize her a little bit and get her use to the touch and approach of others. That's my input!
Toby was doing it for a while so I started holding him when anyone would enter the house and of course he would never pee on me so with as time passed, I would start leaving him down with people he was familiar with and any "newbies" he did not know, I would simply hold him until he was comfy with them being in the house.