Update - new Yaris & the Learner Driver - hootie
I know Back Roomers like to know the follow up to enquiries on here, so, if you remember the assistance I sought before purchasing a car for my daughter to drive - this is what has happened since.

Took the general consensus of advice and bought a new 1litre, manual, petrol Yaris T3 delivered on 1st September.
Car has been driven by 19 year old daughter, myself and my other half - all get along very well with it. Got what we thought was a good deal with insurance from Tesco (daughter named as main driver) so altogether very pleased.

Daughter took her first driving test yesterday, and passed, despite having the examiner that none of the instructors want their pupils to get (she got only 3 minors, and one of those was for slowing down on a housing estate with a 30mph limit. She'd seen unsupervised little kids on bikes, and thought more care was needed)

She drove all us out last night for a celebratory meal. She drove her sister to school today, thereby completing her first lone journey on the way back - and she's just taken herself off to her part time job in town.

So far, so good - but I suppose now the nerves will really start (I mean mine!)
..............

Oh and, once she has a bit more experience of driving on her own, we plan to get her some lessons just on the motorway - Passplus doesn't seem so necessary as she has already done bad weather, town centre, rural and driving in the dark as part of her ordinary driving instruction - and having got the insurance sorted, there is no financial gain to be had atm. Although, the new magazine that the DVLA give out when you pass your test has am IAM course for £75 (-£10 discount for under 25's until 31st December) and completing that sucessfully also leads to insurers' discounts I believe?
Update - new Yaris & the Learner Driver - eMBe {P}
hootie - good to have the feedback. The IAM course is well worth it, regardless of any insurer's discounts. It is a life-skil worth having; and should make your daughter a better, safer driver; and could well help prevent accidents and any consequential loss/hassle/injuries/etc.
Update - new Yaris & the Learner Driver - David Horn
This might in fact be extremely dangerous, but I didn't have any other lessons after I passed with one minor 12 months ago, for starting the engine in gear with the clutch depressed of all things, which I felt was a little unfair. Also, haven't had any accidents (or dents) - touch wood!

Anyway, I practised on a busy dual carriageway near my house, and then a week later took a 300 mile trip from Exeter to Rochdale. The most important thing on motorways, imo, is to check your blind spots, especially over your right shoulder, before pulling out. I have an intense dislike of people who sit there, and will generally slow down to avoid them. Paying attention and always assuming that other drivers are complete idiots also served me well.

Finally, consideration is always important. If you're in the middle lane and see another car in the inside lane catching up on a lorry, move out to let them overtake. That way they don't have to stamp on the anchors.

I'm sure there are lots of other tips that I've missed - perhaps someone else could contribute a few?

Update - new Yaris & the Learner Driver - DavidHM
Congratulations to her daughter and I'm glad it's going well.

IAM is an excellent idea (says he who keeps meaning to do it...) but at her level, Pass Plus may be more appropriate as it is designed to introduce her to situations (motorway, night, etc.) that she hasn't enountered in normal lessons. It's also more widely recognised by insurers than IAM.

Also, you should probably confirm to the insurers that your daughter has now passed her test as she is probably strictly speaking insured on the basis of being a provisional licence holder.