wishes she said no when we had our wedding

I think she means wishes you'd said no when she proposed, but she's probably too embarrassed to admit to your mutual friend that she initiated everything by proposing.

She said she was afraid she wouldn't meet anyone and be alone so when I came along she settled

This means she isn't a catch, has low prospects, and now that she's older with kids her prospects are even lower. Maybe being alone will do her some good, to make her realize how utterly ungrateful and unrealistic she is. It's funny she proposed and she planned for you both to renew your vows but she wishes she wasn't married to you. It sounds like you're the innocent bystander who was swept up in her choices.

If you aren't happy, how long before the youngest is 18? Does your wife work?