Piedrafita to O Cebreiro

A friend is getting a bus to Piedrafita from Madrid. She arrives at 1pm.
Some posts say that Piedrafita is 3km from Cebreiro and others say that it is 5km.
Does anyone know the exact mileage? She wants to decide whether it is worth sleeping over at Cebreiro or whether to continue walking to the next albergue.
Anyone got advice?

Thanks for your advice. I stayed in O Cebreiro in 2002 and it was a cold, rainy, windy, miserable climb up and down the mountain with no views through the mist and cloud. In 2004 the sun was shining above the clouds and it was beautiful. In 2007 we stayed at La Faba instead and only stopped in Cebreiro for breakfast.
These ladies are on a tight time schedule and also a tight budget. If they stay in Cebreiro it will have to be in a hotel.
I have suggested that if they want to walk on the Camino path - the one that the guide book describes as a beautiful route up to O Cebreiro - they could ask the driver to drop them off before they get to Piedrafita - perhaps at Vega de Valcarce (about 7km before Piedrafita and 11.5km from Cebreiro). From there they can join the beautiful Camino path described in the CSJ guide from just after Ruitelán that 'goes up very steeply for about 8km to O Cebreiro'.
2.5km before O Cebreiro is Laguna de Castilla which has a good private albergue where they could book a place. http://caminodesantiago.consumer.es/albergue-la-escuela
The next day they'll walk the extra 2.5km to Cebreiro in the morning - it will be beautiful - and then carry on walking to Triacastela.