At a germination rate of 60%, 25 seeds will yield 60/100*25=<<60/100*25=15>>15 plants.
At a germination rate of 80%, 25 seeds will yield 80/100*25=<<80/100*25=20>>20 plants.
In total, she will have grown 15+20=<<15+20=35>>35 plants.
If 80% of the plants developed flowers, then she will have grown (80/100)*35=<<(80/100)*35=28>>28 plants that produce flowers.
#### 28