How to do I help my girlfriend accept that I have a child from a previous relationship that will stop me doing certain things?

M31, F24

My girlfriend is against the fact I have a child so much that we don't talk about it at all when we're together unless we're arguing.

I've been dating this girl for well over a year and she was aware I had a child from the start. Part way through us dating the child's biological mother stopped contact.

I was distraught and my girlfriend was very comforting at this time. In the end I had to apply for court to grant access which took a good few months to get arranged. I now see my son every other weekend and every other Wednesday with some additional dates throughout the year.

No matter how much I try to make time for my girlfriend and take her out on dates she always complains on the weekends I can't see her. Sometimes resorting to saying things about my and my child and that whole part of my life.

I even recently took 4 days off unpaid just so we could have an extra holiday together. But there's still the issue that I'm only available 1 day of her birthday weekend (which I arranged). And that I have my son for 2 weeks straight in August.

I understand she's a lot younger than me, so I always make the effort to make sure we have something big to look forward to for just us. But it seems like I can never do enough.

I've tried to explain that I'm always gonna try to be there, but there's gonna be times where I can't make it even though I tried my best. It feels like she sees it as me not being there means I didn't try hard enough.

I really don't know what to do to make any of it better. Recently it feels like every solution has 2 more problems.

I love this girl and we always have a great time and love each other lots when it's just us. I just think she doesn't like any other part of my life so much it causes arguments.