Appointment for NI number

[scoobydoolondon]

My wife has recently been granted her first 30 month Spouse Visa and we have an appointment next week at the JobCentre Plus.

We've been told to bring in her Passport, BRP and proof of address (will take a recent bank statement) and Marriage Certificate.

What happens at the appointment? I was told they'd ask her why she wanted a NI number? To be honest, as she is pregnant she won't be working for a few years but I thought I'd get all the "admin" issues out of the way now that she has her Spouse Visa. Also, we have savings and I want to transfer her savings into an ISA, which requires a NI number. Is it ok to say this?

https://www.gov.uk/apply-national-insurance-number states
'Jobcentre Plus may write to you and ask you to come to an interview where you’ll be asked about your circumstances and why you need a National Insurance number'

Also, how long does it take for the NI number to arrive?

thanks