I could be a lot of the changes in her life all adding up and this is how she relieves stress. A very easy way to control her need to potty is to control her food intake. Since you'll know when she ate, you'll know when she needs to potty. I'd definitely recommend giving it a try. It might take a few days for them to realize, Oh I only get to eat now.. but they'll catch on.

When you start a routine.. I'd pick up the food bowls the night before.. let them nibble until 7 or 8.. and then pick them up and no more for the night. Then offer food in the morning, leave the bowls down for 15-20 minutes. Let them eat what they will, may not be all of it the first few times, until they catch on, but this is ok. Then offer dinner (10-12 hours later) and again, only leave the bowls down 15-20 minutes. Eventually they'll realize this is when they eat now.

Also, put them outside while you prepare the food, and then again after they eat, to ensure that they both go potty. =) Good luck!