It sounds a lot like typical behavior for her age range. Very important: Is she talking much yet? I ask because its very frustrating for a child to have SO MUCH to say and no means to say it. She is probably overwhelmed with feeling (missing mom, new babies, etc etc) and its not coming out like she wants it to.
Also, how often are her cries being ignored?
"but she says she tries to ignore the whining and crying but that doesn't help and also telling her to stop whining/ crying only makes it worse"
While I agree that this can be very effective, its not good if she isn't talking a lot yet. If she is crying, there is probably a good reason for it. Even if its just to say "Hey, I need some attention". That is an important issue with her. No matter what everyone says, you're not going to spoil her by giving her too much love.
Good luck!