If the school that she's doing it at - and the instructor she's doing it with (ooh, err, missus!!) - are both approved....yeah.
Came back with an edit to say "However, is she aware of the nightmare of written examinations that she faces for the purpose of gaining an I/R - is she going to fly a suitably equipped aircraft when she has an I/R - and does she need an I/R" (I said "NEED").
The are nightmarish to get - and hideously expensive to maintain - but wonderfully useful if you NEED one.
Is the airfield she intends to fly into suitably equipped? There is little point in having an instrument rating and then trying to fly into some grass airfield with a 600 metre vis and 200' cloud ceiling.
Having said all that - the TRAINING could well be a lifesaver - even if she didn't get the rating.
Would suggest, however, if that if she really wants to do it.....do the written examinations first.