Don't worry about it. They won't forget mommy. It's a bond like @gcpaschal said

I went back to work 6 weeks later and to me my daughter just knew of this face. As she got older it got stronger and stronger and she knows me and daddy are her protectors. She knows she take care of her. She looks for me all the time and even with the time my husband spends with her our relationship is different. We have a bond.