You don't need to do anything differently. I'm a mother to an older teen daughter and I can tell you with certainty that this is completely normal. Your 2.5 yr old is very perceptive. She knows you will be there regardless. She knows you are always there. She knows she doesn't have to do anything at all to get your attention. That's the best thing in the world. Even today, when there is some kind of trouble the first person my DD calls is me. For all else, there is her Dad. I keep telling her that all the good news goes to Dad and all the stress comes to me. If she doesn't call or text, I know all is well. Your DD may play more with Dad and want to expend more energy to get his attention but when she's in need you will be the person she turns to. You are probably feeling insecure because you lost your family young. Don't. Mom is irreplaceable, she isn't rejecting you or not feeling less love towards you. She is very secure in your love for her. Like others have noted above, it is a good idea to work with Dad and present a unified front. As she grows older she shouldn't play one parent against the other.