I am sorry to hear about your situation. Unfortunately, if you are not the biological parent of the child, then you do not have parental rights. If you can show your wife is unfit, and has given up her constitutionally protected rights as a parent, then as a 3rd party, you may get custody of the little girl. You would have a much better chance of getting custody of your sons, however.
Best wishes,
Shonnese D. Stanback
Attorney
The Rosen Law Firm
4101 Lake Boone Trail, Suite 200
Raleigh, North Carolina 27607
919.256.1534 direct voice
919.256.1667 direct fax
919.787.6668 main voice
919.787.6361 main fax
NCdivorce.com
email: sstanback@rosen.com
The response posted above is based upon the limited factual information made available and is not intended as a full and complete response to the question. The only reliable manner to obtain complete and adequate legal advice is to consult with an attorney, fully explain your situation, and allow the attorney sufficient opportunity to research the applicable law and facts required to render an accurate opinion. The basic information provided above is intended as a public service but a full discussion with an attorney should be undertaken before taking any action.