Sorry it's a bit big (I struggle with pictures!). And I hope this post is in the right place.

Can anybody tell me what this is please? The information I have is that it grows rapidly in both height and spread; has pink flowers and the leaves take on a reddish tinge in the winter.

The leaves are small, dull and soft, a light green and very slightly serrated, and not in pairs. The leaf stems are reddish.

This plant was a cutting and it's in it's first year.

The lady I got it from called it 'Rampant Rain'.

I'd like to know a bit more about it before I plant it in the garden.

Thank you - hope you can help.