Adding data to old number

[Ben127]

Just paid off the existing balance of my XR on my mums account and opened an account in my own name and upgraded to a 13 Pro, been told I can keep my old number and put my old sim in my new phone but I can't add any data for
example 2GB of data a month. Can I add
data onto my old number or do I have to
activate my new sim to add data. Any help would be much appreciated. 

[GD1]

@Ben127  Your old sim re mains on your parants account, yuou cannot tranfser the ne ber from one Sky sim to another.

If you activated the new sim you will get a new number.