Looks like Ground Elder to me, and it is a B to get rid of, best to use a weed killer that is like a large lipstick, paint it on the leaves, thats how I ended up getting rid of mine and I had loads of it, it is an long chore but worth it in the end.
Good Luck :o))

Thanks Ladyessex, I did wonder if it might be but wasn't sure. I will let my friend know.

I would wait until the bluebells have died back then spray it with roundup. It would take forever and a day to treat each leaf individually.

I had ground elder in a border when we first moved in to the house. I double dug and sifted the soil to remove the underground rhizomes. In another area I sprayed with roundup especially late autumn when the plant sends nutrients [+ the weedkiller] down into the rhizome ready for winter. This tends to be the most effect way of killing it.

Thanks for your suggestions, I will pass on your ideas to my friend.