This painting at Tredegar House is of Blanche Parry (1508-1590) and is still owned by Newport Museums and Galleries. The fashion is very similar to that of Queen Elizabeth I, but Blanche was a Woman of the Bedchamber to her, so that is perhaps not an entire surprise. I suspect that this role, which was nearly always held by aristocrats and was more about travelling with the Queen and offering social support, was likely rather an interesting one and it came with some significant power. Parry was an aide to the Queen for over fifty years, so she must have picked up some considerable gossip during that period.
It might have been painted by Marcus Gheeraerts the Younger (1561-1632) who was perhaps best known for the Ditchley Portrait of Queen Elizabeth. The information about the painting also notes that the frame is from the eighteenth century, so it is later than the artwork itself. The realistic and grand artwork is also very much a statement of power and influence, no doubt a source of some pride to her family.
Blanche wasn’t directly linked to Tredegar House, but she was connected to the Welsh Marches, so perhaps there was some family history interlinked there. Or it might be that Newport Museums and Galleries acquired this artwork and thought that Tredegar House was the best place to just pop it.