Ustad our relatives just wished my sister her birthday today, she wants to reply to them in a way that isn't rude but at the same time condemn birthdays, what would be wise to do in this situation so that they don't feel bad but at the same time learn why it's wrong ?

Ustadh AbdulAziz al-Haqqan

Making dua for them for their care for her and wishing them that everyday in sha'a Allah is a happy day as we dont celebrate days except for the Eids may Allah reward u.