I'd say she's committed at least two offences. Under common law her words to you, if proved, constitute behaviour likely to cause a breach of the peace.
Under the road traffic act she has committed an offence by failing "when given reasonable opportunity" to report an accident in which another party "was or may have been" injured. Doesn't matter whether she was aware of it or not at the time, it should be reported as soon as she becomes aware of it (ie when you told her).
She's also quite possibly invalidated her insurance, as she's probably required to report any accident to them as well. If you keel over and die and its shown that it was a result of (say) a blood clot caused by the impact, then your estate might have a claim against her. If she hasn't informed her insurance company in good time then she'll be in trouble.
As to any insurance claim, the key factor is whether you were proceeding "correctly". This appears to be the case, and her behaviour behind the wheel seems not to have been very good. However your running colleagues were not proceeding "correctly" by running on the wrong side of the road, so the driver could, in theory, make a counter claim against your club, again provided she can show that she was proceeding "correctly" (which she does not appear to have been). Its actually quite hard to say without seeing the site of the accident.
I actually had a claim made against me when one of my sheep was knocked down and killed by a motorcycle, having got out through a gate that had been left open by a rambler. The court found that I had taken all possible measures to stop the animal straying and that the motorcyclist had failed to heed the warning notices, and speed restrictions, and was therefore not proceeding "correctly". As the sheep was actually walking down the road towards the motorcyclist, it was deemed to be proceeding "correctly" as it was clearly visible, and the rider could have stopped had she been travelling "correctly" (ie not speeding and cutting the bend off).
Have to say that the idea of my late sheep proceeding "correctly" made me smile a little...