My sister had this towards the end of her second pg, she was admitted to hospital as they were worried about her lungs, turned out that it was a sign of labour as shw had her baby 2 days later (3 weeks early). The meds they gave her for her shoulder (pain was severe and crippling) masked her contractions so they only felt like mild BH, next thing her waters broke and baby was here an hour later!
Maybe just let her know just in case.
Good luck and I hope you manage to go away!