I agree with Vash and Blue. How motivated is she to keep the family together and make life easier for the child? And trust is easy to loose and hard to get back. You will have a lot of work cut out for you to convince her that she can trust you again. However, on your side you did come clean with her when you could've kept this a secret.
My advice to you is be understanding and accepting of her. Understand and accept her decisions. Let her spend some time thinking about them and potential consequances. Show your support. Show how you have changed and aren't the kind of person who will betray her trust again. It won't be easy, but little by little there is hope that you can get that trust back. It's been known to happen even after more serious issues.
Don't cry, don't regret and don't blame
Weak find the whip, willing find freedom
Towards the sun, carry your name
In warm hands you are given
Ask the wind for the way
Uncertainty's gone, your path will unravel
Accept all as it is and do not blame
God or the Devil
~Born to Live - Mavrik~