It's not even in the top 10 attributes for a softball player. Lifting or not lifting weights will not have a meaningful full impact on runs scored or allowed.
Most players are sufficient in terms of strength to play this skill-based game.
You can verify this at your next tryout. Look at the attributes they are concerned about/test for.
A lot of what my 14yo pitcher is doing looks like strength training to me. Pitching short distance after sitting on a box and standing up with one leg. Pitching drills on a bosu ball for core strength. Scap pulls.
It’s different from what I did as a swimmer - but it’s very much strength training and it very much has impacted runs allowed in her case.