Can my mother transfer payg sim number to new payg sim?

[crumbles]

my mothers friend gave her a used iphone 7

currently she uses an aging 'vodafone smart first 6'

the sims are different. the iphone 7 needs a nano sim

if she goes into a vodafone store can they transfer her phone number from her existing payg sim to a new nano sim that is also payg?

i looked online but all i saw was transfering from payg to contract and vice versa

she definitely needs to keep her old number and does not want a contract, just her normal big value bundle

[AnnS · Accepted solution]

Your Mother will need to do a SIM swap @crumbles , this will need to be done to a plain new blank numberless SIM.  See here: SIM swap . This can also be completed by visiting a store.

Please note this will be a multi SIM. Further information here: SIM cards Multi SIM 

When the number she is keeping has transferred, your Mother will need the correct APN settings, there is further information here: Device Guides