Parenting Plan

My husband and I separated a few months ago and he moved out earlier this month. We have a five year old daughter and he has three children from a previous relationship. The three children are all over the age of 18 but one child has learning disabilities. We are currently splitting our daughter's time 50/50 and we are doing this on a rolling three days between us. To be honest I am finding that this doesn't really work for me as unless my time with her falls on a weekend I don't really feel that I am spending quality time with her.
I have discussed alternate weekends with my husband and he outright refuses to consider it. His response was that he would never have a weekend off (his child with learning disabilities was visiting alternate weekends until we separated). I have suggested that he has our daughter and his child with learning disabilities at the same time as they adore each other but he says it's not fair on either of them to have them at the same time. I know my daughter will miss her half sibling if she doesn't see them. I don't understand his refusal and when I have tried to challenge him he just refuses to explain what the issue is and just talks over me/at me. Any advice please as we are amicable at the moment but I can feel things heading in the wrong direction. Am I being unreasonable??

Welcome to Wikivorce, although I'm sorry you have a need to be here.

Parenting plans will only work if both parents are in agreement re child arrangements and are committed to working together as co-parents.

It's not unusual for parents to try a number of different arrangements before finding one that works best for everyone. You could use our parenting plan as a template for setting out what you think the best arrangements are for your child. divorce.wikivorce.com/guides-children/ag.../parenting-plan.html

Is it worth suggesting that you try your proposal for him having your daughter and his older daughter at the same time - even for a short period, just to see how it goes. It may work very well, and if it doesn't then at least it's been attempted, and you can then look another arrangement.

mediation may be a good next step to take if you are not able to resolve matters between yourselves.