Hi,
Welcome to the ehealthforum. I am glad to help you out. Your girlfriend seems to be suffering from what is known as hypoactive sexual desire disorder (HSDD) or decreased libido. One of the commonest causes of the same is fatigue.
The monotonous routine & daily burdens of life tend to decrease oneâs sexual desire. Oral contraceptives are also known to cause a decreased libido as one of their side effects but thatâs not very common. So check this possibility also.
Watching some erotic movies with your boyfriend and prolonging the foreplay can also help in ensuring the orgasm and improving your libido.
I sincerely hope this information helps. Take care.