I'm Lucy, and I'd be happy to answer your questions today. I'm sorry to hear about your situation.
The law doesn't make any distinction between a biological grandchild and one related through adoption. A grandparent may bring a cause of action requesting visitation with a grandchild when they can show (a) that the parents are not married or that one of the parents is deceased, (b) a pre-existing relationship with the grandchild, and (c) that visitation is in the best interests of the grandchild. The fact that the parents are in agreement would present a barrier if they were still married, but it doesn't automatically preclude you from getting time when they're divorced.
Any visitation order would remain in effect until the child turns 18. She will be able to testify as to whether she wants to be able to see you because of her age, and the judge will consider her opinion.
The Indiana government does not make forms available online for this, possibly because it's a fairly new area of law (comparatively speaking). One option is to visit a law library and check out books to show you what a Complaint might look like. The other option is to hire a local attorney to help. Because the law tends to favor parents, that might make things a bit easier for you.
If you have any questions or concerns about my response, please reply WITHOUT RATING. It's important that you are 100% satisfied with my courtesy and professionalism. Otherwise, please rate my service positively so I am paid for the time I spend answering questions. If you are on a mobile device, you may need to scroll to the right. There is no charge for follow-up questions. Thank you.