She should be having housetraining issues for a good few months yet, too.
She is only a small puppy and really it will be 6 months of age before she us fairly reliable and usually a year til you can say they are housetrained.
Crate training is a big help and useful for other things too, so many of us will definitely recommend it! A crate is the safest way to transport your dog in a car for example, and a crate trained dog can go with you easily on holidays and stay safely in a hotel room, etc..
There is info on crate and house- training in the Library section, and recommended books -- Shirlee Kalstone's book on housetraining is my must-have recommendation. Remember the shortest way to housetrain a dog is PEOPLE commitment -- 100% supervision, 100% of the time, and in the crate when that cannot be managed (unless that means long periods of time as puppies cannot hold themselves -- full time workers unavoidably have a much harder and longer time housetraining and may never have a totally reliable dog unless they take time off to focus on training their dog).
It is important to have expectations that match 1) the age of a puppy; 2) the learning ability of an individual -- they all differ and all go at different speeds, just like people; and 3) your time and training commitment to your puppy.
The last is the most important -- it is never the case of a puppy that cannot learn; but is often the case of an owner needing to give more time and effective training! :lol:
Positive methods, never any punishment, 100% supervision, and setting a puppy up for success as much as you can (eg do not create the circumstances in which a puppy can make a mistake and go inside -- by not supervising, leaving too long without taking out, forgetting to take out at key times like on waking, after meals, after drinking, after playing -- make for easy and fast training.
If you use the 'search' function on the site you will also find many, many threads with housetraining advice.