welcome to HealthcareMagic..
according to me taking i pill
for longer duration is not good it could further affect her irregular menses adversely , moreover when she wud want to conceive this will affect easy conception also...
better would be both of u should come nd meet a gynae , and learn about calender method and other methods of contraception
like barriers like condoms or female condoms etc...
also to correct her mensural disturbance, ayurveda and panchkarma will be of great help,
and this will also look after her mood swings ....