Handmaidens, called bruinneall in Selkie, differed in their role and purpose much during the Age of the High Kings and after that until today from international standards. Their primary role was always to both assist and protect their Lady, their secondary role to provide for the others of their Lady's entourage, for example by supplying the bodyguards with food.
None of their purposes was sexual, but they were schooled in entertaining, namely by dance, song and music, games and other forms of entertainment. The skills in these matters decided about the worth of a handmaiden on both the market and for their Lady, their deeds reflected back onto their Ladies.
Should a handmaiden bring dishonour to their Lady, it was hers and hers alone to punish her in the way she saw fit, but without killing her. A too harsh punishment however could bring dishonour back to the Lady in question. On the other hand, a handmaiden was under the protection of her Lady, moreso of her household. A crime against her could have serious consequences.
If a handmaiden found her love, she would ask her Lady for permission to leave her services, which was usually approved. The handmaiden would now stay connected to her Lady and her family until her dying day. Getting offers from another house to change Ladies was highly frowned upon.
Nowadays, handmaidens are mostly gone, with some of the more influential and richer houses maintaining a staff of personell, who's female members are still called handmaidens, though their tasks differ nowadays (the handmaidens of Arbhar House near Ironcastle for example are tasked with taking care of the garden and cooking). Not only female persons of high influence have handmaidens nowadays, but also males (the steward of Arbhar House is a man, for example). Some hotels and inns provide guests in their most luxurious suites with handmaidens.
Two of the best known handmaidens are Aífe the Banshee and Tea the Handmaiden, made immortal by the account known as The Ancient Gathering and similar accounts from the 1st century BCE, many written by Sírlám the Scribe.
Tea is also seen as a good example for the position of the raicleach, or cat, the reason for the cat ears and tails mostly seen on pictures of her. As raicleach it was Tea's mission to serve her lady without stepping out of the shadows herself, rarely making an appearance, but being felt regardless. If the sign of the position indeed was a pair of cat ears and tails is, as researchers note, debatable, but cute nonetheless.