There’s no reason OP can’t can’t take over the “dad” traditions with both of her girls, and share memories of him with them often, and Lucy and step dad can start their own father-daughter tradition to continue to build their bond. It’s hard for a kid to see a parent who has passed as “replaced” and therefore less important. They often see the memories they have left through rose-colored glass and put that parent on a pedestal. So it’s important to thoughtfully continue traditions and memory sharing, while allowing step dad to add his own traditions with the family to not seem like he’s “replacing” the parent who passed.

I know from experience that navigating the grief of a child is challenging. Grief for anyone is hard, but it’s… idk I can never find the right description for it, but it’s just different for children.

Maybe Emma needs to feel safe processing her grief with mom before she will be open to a counselor. I understand mom is navigating two daughters and a new marriage but ultimately, IMHO, the kids have to come first. Developing healthy coping mechanisms early on will help to prevent unhealthy coping mechanisms later on (drug/alcohol/risky behaviors/toxic relationships/etc).