I do not know the title of the children’s book I’m looking for.

All I know is that the book is about, I believe, a little girl (not sure if real girl or animal girl).  I want to say it may be a mouse family or pig family, but either way she has a big family and she tries to take a bath but someone is in the bath, then she tries to read in her reading spot, which is a big rock outside but someone is on it.  Then her family either moves or leaves for the day and she is left alone in the house which at first she enjoys as she takes a bath by herself and reads in her favorite reading spot.  But pretty soon she realizes that the house is empty and she is lonely.  Eventually, her whole family returns home or comes back to get her and she’s happy again.  I thought the name of the protagonist was Petunia or something similar to that, but I couldn’t find it when I searched.