Kitten often bullies my older cat. Any hope that this dynamic can change?

We are fostering the kitten (Korra, about 3 months old), with a possibility of adopting her at the end of the foster period, which is very soon. Our hope when fostering Korra was that she and the resident cat (Juniper, 9 years old) would become good friends. We introduced them slowly - exchanging scents, hanging out behind closed doors, etc - and eventually they were able to coexist in the same space. It’s been two months. Multiple times a day, without fail and without any provocation, Korra seeks out Juniper for play by jumping at her. This is a big surprise, because we were initially worried about Juniper overpowering Korra, given her bigger size. However, Juniper seems to try to fight back for a little while before backing off, and giving up any territory or food to Korra. Sometimes Korra can be relentless in her pursuit of Juniper, and we have to either distract her with play or separate them. We play with the kitten tons, and regularly tire her out, but she always finds the energy to harass Juniper. Obviously, this is not ideal.

Hoping to get an opinion from the community here on whether there’s any hope in stopping this from happening, or whether we need to accept that these two cats aren’t meant to coexist in the same home. Really appreciate any feedback and advice.