Hi. If it happens again, get a vet to check things out, just in case this "accident" is linked to a physical problem occurring. My opinion, for what it's worth, is to avoid allowing her to sleep in your bed. It could be she is scenting, particularly after the grooming, or that it was simply an accident. As you have already said she tends to pee on any carpets or rugs you have (had) in your house, I think this is actually more a behavioural issue - and the answer is to start house-training her right from the start again, as you would a new puppy. You shouldn't need to crate her for this, just make sure she is let out once an hour, supervise her, then when she pees outside, give her lots of praise. Keep repeating this process over a few days and she will get the message. Of course, it's vital you always let her out first thing in the morning and last thing before you go to bed - and don't let her back in until she has had a pee. Then, praise, praise, praise.