My 11 year old wants invisalign instead of braces. i don't know what to do. her teeth aren't in bad shape ?

This is a personal: choice....depending on her orthodontist's recommendation. If there is a difference in cost, that may be a deciding factor. I would discuss the options with the orthodontist.

First things first: 1) consult with an orthodontist 2) determine what treatment is best for her and 3) follow through on what is best since you are the parent and it is your responsibility to make those decisions. What she wants and what she needs may be different

Consultation: Please see a fully qualified Orthodontic Specialist for an initial examination (usually free). The Orthodontist will evaluate your child's need for treatment (or not), treatment length, and the appropriate medicine (braces or clear aligners--they are NOT equivalent (aligners are not as effective and take longer). With full knowledge you can then make the best decision for your minor child.

Ortho Consultation: Many orthodontists offer an initial complimentary consultation and free exam. See an orthodontist to help determine the right treatment type and plan for your child.