Congratulations on your new puppy.
She is only four months old, it is going to take awhile, potty training won't happen overnight. I would not expect or LET her outside by herself to potty at this young age. It will take time, but if you are patient and persistent and repetative, go out with her every time and praise/treat her, she will get it.
Also, if you cannot watch her like a hawk when she is with you inside, consider getting an expen where you can confine her with toys and water, etc.
Remember, four months is very young, she does not know what to expect right now, and her whole world changed when she was taken away from her mommy and littermates. If you can look at it from this perspective, it helps with the patience