Both Search: WWW and Birthcare Center are comedies and female centered dramas from TvN. Both have different story but I believe that you'll love Search: WWW if you liked Birtcare Center.
Different parents with different stories and parenting styles
Befriending each other and learning from said experiences
Both series are heartwarming and short
Birthcare Centre is comedy drama about career female lead and she's trying to have a baby.
SKY Castle doesn't have much in common. It's more focused on education than mothers/parents and their childs. But it's also female centred plot.
Birthcare Center has a more mature approach considering it's showing the life of mothers with newborn babies. Both dramas have great sismance vibes and showing females supporting each other. They have great comedy but also give meaningful messages. Actor Yoon Park played in both dramas.
In particular, the emotions of the female protagonists in both series, the maternal instinct, the attitude towards husbands and the way they blend the approach of women to the outside world with comedy are very similar.