Hi thanks for your question.
The aim of foreplay is to make the partener ready for sex.Foreplay increase sexual drive and increases vaginal lubrication
to make penetration easy .If she is ready for sex without foreplay,it is ok.It is not an issue for her.However it is a serious issue for you.You can sort out this issue with her by talking to her,making her understand the impotance of foreplay.Finally help from a psychologist
should be sort.
Hope this answers your question.