For those who co-parent

My hubby and I have 3 kids. Except that my oldest (6years) is from a past marriage. Her father was never interested in seeing her much since she was 4 months old. We separated when she was 4 months and I got with my now hubby . He's practically raised her. Her bio father only has seen her about 2-3 times a year since then. All of a sudden he wants more rights and time sharing with her (new lingo courts and lawyers are using also we have no "custodial parent" here in Florida anymore 😒) So the judges don't care that he never had interest before and barely knows his child and so we settled with him having one weekend a month PLUS alternating holidays- example he gets her spring break this year. Well the past 2 weekends that were his to have her, her little sister misses her so keep much and cries all day asking for her. And I miss her so much that I cry 😭 (I'm a Stay at home mom so I'm pretty close with my kids)  I don't feel it's fair but at the same time I know it is and he has right to a relationship with his child. I don't know what I'm asking for here really. A way to cope? Anyone else gone through anything similar?