what does it mean when a birth mother formally opposes an adoption?

[Abena]

My sister's little girl (aged 3) has been with her for a year. The adoption will formally go through in a month. Suddenly the birth mother has put in an opposition to the adoption. She gave her child up when she was 4 months and the child was with foster family until she came to live with my sister. Does anyone know about this process, what happens and has anyone had experience of it? The social workers say its unlikely she will go through with it and even if she did she would not be able to disrupt this little girls life as she is finally settled and happy. The reasons behind her being taken into care in the first place are enough to suggest that the little girl was saved from a very bad situation. Any advice out there?

Hurray!

From what I have heard it is also v.common for birth parents to withdraw at the last moment. It may be that someone sensible had a chat with her and pointed out how stressful the process would be for her. Trouble is for every one person telling her the truth there will be 4 saying 'you should get her back, you can do that you know, I saw it on the news'.
I used to work with birth parents (in an indirect way) and they would often call to ask about stopping adoptions. When I got the full story it was pretty clear that the process was much too far gone.
It was sad that the birth parents seemed to have no real clue about what had gone on.
Kristina dont apologise it was me who got it wrong . Hmmm dont know about being a good person. Believe me I have some pretty murderous thoughts about madam. I suppose its better for all of us if I try and rationalise everything she has done.