If I understand it well, given that she is also the spouse of a British citizen, she doesn't need to wait 12 months after obtaining settled status in order to apply for Britihs citizenship.
You can apply for British citizenship by ‘naturalisation’ if you:
are 18 or over
are married to, or in a civil partnership with, someone who is a British citizen
have lived in the UK for at least 3 years before the date of your application
You can apply as soon as you have one of the following:
a permanent residence document to prove you have permanent residence status
indefinite leave to remain in the UK
‘settled status’ (also known as ‘indefinite leave to remain under the EU Settlement Scheme’)
indefinite leave to enter the UK (permission to move to the UK permanently from abroad)
Could you please confirm, that my interpretation is correct. Thank you.