I had a mut’ah marriage contract with a woman. The contract was for couple of years.

1) During that period going into the first year I lost contact with her and she got married while still under her marriage contract with me. She got married not mut’ah but regular marriage. Was her marriage to the other person valid?

2) Where do I stand with her? I just found out she got divorced, can I marry her?

1) No. Her marriage is void.
2) If the two-year period still has not expired, she is still your wife.
But if the period has ended, you can marry her with a new contract, but after the end of her iddat from the man who entered her with a void contract, and the waiting period (iddat) is 3 menstrual periods