ah, it all becomes clear! thank you for brilliant information!!
can I trouble you for a couple more answers?

can she take the 'life in the UK' exam at any time? she wants to get it out of the way asap if poss.!

is the ILR process expensive?

we've got a 13 month-old boy, loads of pictures, date-matching passport stamps and probably loads of old mail so I reckon we'll be covered for evidence.