Our babies share a birthday!!
Although Tia isn't as small as yours (was 2 lb, 10 oz at 13 weeks) and has been able to hold it since we started training. I crate train at night and during the day use a treat and praise method for potty training. You really just have to figure out what you are comfortable doing. I use a playpen when we need to go anywhere and place her food, water, a wee wee pad, a couple of toys, a blanket and one of my t-shirts in there with her.
I'm sure someone else will be more helpful than me - but YAY for our babies having the same birthday
What's her name? We'd love to see pictures!!