Thank you for your query.
As she is already 8 days over her due date, you should anyways take her for a check up
Labour pains would be intermittent, associated with palpable contractions, that is intermittent hardening and relaxation of the uterus
They would be referred to the back and the groin area.
ALso, they would generally be associated with signs like vaginal spotting / bleeding or mucoid discharge.
They would not respond to painkillers as a rule.
If you are not sure what kind of pains she has, this being her first pregnancy
, it is better to get her checked.