Note: The DearEsq free 'ask a lawyer' site is offered as a free informational service to the public and is not intended as legal advice. Laws vary from state-to-state, and in addition every situation is unique, and relevant facts may not be known. The answer to the question posed below may not apply to in your state or to your situation. For legal advice in your state and your situation you should consult with an attorney in your state who is familiar with the rules and laws in your state.
“Can my sister-in-law adopt my daughter without my say while I have sole custody, even if she has lived with her for over a year?”
No, however she can move to be made her legal guardian and, in some states, if she claimed she didn’t know where you were and couldn’t find you, they might allow a more permanent arrangement.
This all begs the question: if you have custody, why isn’t your daughter with you? This needs to be addressed, and sooner – much sooner – rather than later so that you and your daughter don’t find yourself in a difficult situation with respect to the courts.