As far as I'm aware its normal. She's probably growing some 'childbearing hips'.

I think girls with wider, 'fatter' hips have an easier time with childbirth...

Also, at 19 she could still be going through puberty. Some contraceptive pills can cause an increase in breast size and breast tenderness. They can also cause irregular periods, even if she has been on the same pill for a long time, the side effects can show up at any time.

Stress, depression, anxiety etc can cause irregular periods.

Best bet though is to go to the doctor's.

...yes, I'm a woman hehe.