Primrose

Posy, Posie, Rose and Rosie could be nicknames. I was also thinking that Prose could be a quirky nickname as well.

The name Primrose was given to 50 girls born in the US in 2015.

One of the prettiest combinations using Primrose that I've seen belonged to an Australian lady born in 1911, called Gwendoline Primrose Ogilvie. However, in the Ogilvie family the name Primrose had been used for boys since at least the mid-eighteenth century and was her father's middle name - in their case it was not meant in honour of the flower but in honour of the Primrose family, an eminent Scottish family to whom they were connected. It is the family name of the Earls of Rosebery and derives from their lands near Dunfermline - it's thought to originate in the Gaelic “prenn rhos” (meaning “tree of the moor”).