Putting her on a feeding schedule and limiting her water intake during the day when your not home will help. Also having a cut off time for food and water at night giving her plenty of time to empty her bladder and bowels is a great idea. Until she is potty trained I wouldn't sugest free feeding if thats what your other is use to.
You may want to try leash training her. That keeps her close to you, giving you oppertunity to correct her and stop her before she has that chance to have any accidents in the house.
I've had much success with cage training also. You welcome to take a look at my tips on training:
www.dawnsyorkies.weebly.com/trainingtips
Good Luck with her and I hope she prooves to be great addition to your family !!