is your little shihtuz hard to potty train if not what and how did you do it?

I have two shihtuz's one we have had for five years. we had a hard time with her at first and then she only went outside and now she has started going potty on the floor again. We also just had our second baby 7 weeks ago. We also have one that is a year old and she goes potty on the floor. We crate her at night when we are a sleep. I hate to do this but we are going to buy a crate for the older dog to use at night and when we are not home.

Yes, I have had my shihtuz for 3 years and she still isnt potty trained!