Friends baby drama

My friend two years ago spectated from his longtime girlfriend and has a 6 year old daughter with. The mom has decided she enjoys her freedom and wants nothing to do with her daughter.

He stared seeing another girl and got her pregnant and is having a tough time with juggling both kids. The new GF is being unreasonable about asking for help. She doesn’t work and he does 12 hour shifts and does all the night work and while he’s home he is the only one caring for the baby . She’s complaining he’s not doing enough and he’s overwhelmed. His oldest is upset because her mom abandoned her last year and now she feels like her dad is doing the same. I want to help but not sure what to do.