I was a in a Methodist wedding this weekend. (1) Does Church consider Protestant marriages valid? (2) The minister or presider was a woman,does this make things worse? (3) Did I do anything wrong by participating in the wedding?

Protestants are not under the same canonical requirements as Catholics to be married in the Church by a priest or deacon. Since they are baptized, the Catholic Church considers their marriages to be valid and sacramental, even though their own theology doesn’t consider marriage a sacrament. In a Catholic wedding, the minister is required as an official witness of the Church, but for non-Catholics the validity of the marriage is not affected by whether the officiant is a man or woman or a minister or a justice of the peace.

Assuming that both the bride and the groom were Protestant and were otherwise free to marry, it was not wrong for you to participate in this wedding as an official witness, although if you thought it might be wrong, you ought to have found out before the wedding.