As an only child, she may be competing with you for your husband's attention. She is assuming more of an adult role in the family. The doctor talked about the adults being on the same page with parenting. It also will benefit you to talk about setting healthy boundaries with your daughter, and gently correcting her when she attempts to assume an adult relationship with either of you.
For example, it is not an acceptable greeting for a child to say to a parent, “What do you want?” Teach her to address you by saying, “Hello Mom,” (or “Hello Mommy, Mother, etc.”)
She may take her adult attitude into peer relationships and attempt to give orders to her peers. This will cause conflicts with her peers, and impede the development of social skills.
Your decisions to work and get an education are not the cause of her issues. Making her a priority is essential, but there is time as a couple to organize your commitments and keep your child as a priority in your family life.
A parenting class or parenting support group could serve as a good resource for you and your husband to develop your plan together to establish and maintain healthy parent-child boundaries. She will resist this change initially, but she will feel more secure when she assumes her natural role as a child with two adults running the household.