Salam, Ramadan Mubarak, Further more on my previous questions, what if we are staying for the 2 or 3 days at my mother’s house? Do we still have to fast fully and pray fully?

Walaikumussalam
Only if you consider as watan then yes whether stay for one day
If you are not considering as your home town (watan) then Namaz and roza are Qasr.
All based on your niyat.
Once person can have more than one watan.
Wassalam
Syed Abul Qasim Rizvi