Wa `alaykum As-Salamu wa Rahmatullahi wa Barakatuh.

I do not see an issue celebrating that day. It is a social event not a religious one. It will become haram if things done in it were haram like drinking wine, spending money extravagantly etc. But if someone bought his mom a gift or took her out for dinner or invited family at home to be with her it should be fine.