Not sure what you mean, exactly.
There’s no requirement for her to have a BRP for a citizenship application. Giving biometrics just means giving your fingerprints and photo to confirm your identity for the application - it does not necessarily mean you get a BRP.
If you already have a BRP, you send it with the application, if you don’t, you just send your passport with the ILR sticker in it instead.
Everyone has to give biometrics for citizenship now, whether they have a BRP or not. It’s just to confirm your identity for the citizenship application and in this case has nothing to do with getting a BRP.
So, if she doesn’t have a BRP, then she doesn’t have a BRP. She ticks the box to say she doesn’t have one, and continues on with the citizenship application, providing her passport with the ILR sticker in it.
When she applies, she will be told where to go to give biometrics for the application, but she will not be issued with a BRP.
Sent from my iPhone using Tapatalk