Yes she can take without break for 7days extra then discontinue But as she I'd only 16yrs old why she is been on yasmin pills from such tender age Kindly do the proper evaluation and as far as possible avoid hormonal therapy If she is pcos try to shed wt if she is obese, maintainance of good lifestyle, avoid junk food, indulge in physical activities such as walking, exercise makes her to have menses regularly