So apparently, someone has lately found my blog using the mystifying search term: “love message for my girlfren mam. (sic)”
I don’t actually have much advice for this person. I mean, I would generally be against writing love letters to your girlfriend’s mother. But if you must, I would advise you to be smooth, I suppose. Write her a poem in an 18th-century Scots dialect, as this seems to be your native tongue.