Take comfort from the fact that at this age, your daughter is far more accepting of cirfcumstances than you are.
If he is disinclined to see her, then forcing the issue legally will simply lead to him seeing his visits as a chore, which will be more destructive for your daughter's well-being than not seeing him at all.
When she is old enough you can explain how things are, but for now, she goes along with the fact that Daddy is not in her life, and you should try and accept that too.
It is wrong, but as you state, there is nothing more you can do. In these situations, we have to live with things as they are, not as they should be.