I clicked no. I like Rose, don't get me wrong but I think you're already getting quite character heavy as it is. Adding Rose into the mix would quite probably detract from certain elements of this that make it one of my favourite stories to read. If you think you can handle it and keep teh character balance then go for it, but, in my opinion, I think the current character balance works quite well with just enough room for an OCloveinterest for Ianto.

The plot you could derive from Rose would most certainly be fantastic but, as I said, it might take away something from the over all feel of this verse rather than add to it.