Sorry to hear that. I'd like to chime in on this one.
I have 3 lovely, well adjusted, funny, principled, intelligent daughters. I do not deserve them.
All 3 were valedictorians of their HS, without pushing by us.
Anecdotal? Perhaps, but harder to argue with results * 3.
I've never before shared this much info about what we did. FWIW, YMMV, etc.
1) Give them the gift of self esteem. Demonstrate your believe in their intrinsic worth, and act out of love only. This does not mean giving them every toy they want, but it does mean make sacrifices when you can for the best aspirations of your kids, and constantly showing them how much you appreciate them. Be sentimental and approachable. I think my kids knew I would have been no less their fan if they were D students.
2) They need you, give them all of you. Don't hold back and don't ever fake it with them. They know you; no double standards! If that movie is bad for your kids, parents can do without watching it. Schedule regular whole-family time and 1:1 time. Family dinners together are important.
3) Humor and curiosity are some of the best tools. Demonstrate them. Memorize funny poems, make music together, show how to take things apart, and keep it all upbeat, even crazy.
4) Don't let anyone else raise your kids. That includes daycare and school systems. I lean toward public school system over homeschooling, and it worked out for us, but that depended on what the system had to work with. Social development and problem solving is important. So are friends. Be involved parents, room mothers, etc. Know the kids in their K-6 classes; they end up on your doorstep asking for dates. Here's the tough part, but it proved extremely important: I barely made a living wage and my wife made more than me when we decided one would stay home. It was her call who would. I don't know if I would be able to look my kids in the eyes if we hadn't sacrificed.
5) Money incentives? Oh ya. Make cash match effort was my philosophy. They got a pittance for base allowances but kept job-journals as they learned to write and were richly rewarded for finding new ways to help. In school, the first A is the easiest, even hard not to get. That last A is a bear, it's the subject they don't like. My kids got $1 for the first A, and the pay doubled for each additional A. They nearly bankrupted me. Long term, the investment works out. The youngest just took her MCAT.