It does in fact sound like your daughter is seeking attention as you stated. Children learn at a young age that acting out will get them noticed. Since this has worked in the past, she will continue to do this unless you help her learn a new way to behave. She is only 10; you cannot expect her to appropriately ask for more attention. Give her examples of what both positive and negative attention-seeking looks like.
You need to know that she understands and knows what your expectations are. Once she does, have her practice with you. For instance, she could ask for some of your time, help with the baby or express her feelings by saying that she feels left out. These are all healthy ways of getting attention.
The basics of behavior modification say that the only way to increase or decrease a behavior is to issue consequences. So if your daughter demonstrates negative attention-seeking behavior, give her a consequence. It can be small, but it must be motivational. Make sure it is immediate, and follow through on it to ensure its effectiveness.
If she does well and positively seeks attention, reward her. This can be as simple as spending 10 extra minutes alone with her before bedtime reading a book, brushing her hair, cuddling – whatever she enjoys. The activity is not as important as the time you spend with each other.