I have a hologram character already made up if I'd be allowed to reuse it. (The game in which she was originally made died.)
Tisha - Hologram (Human appearance)
During one of the routine trades with the Ferengi, they offered over one of their holographic programs in order to sweeten a particular deal. Some rumors circulated among the crew at the time that someone had met up with this particular girl and developed a bit of a crush, but that since her memory banks were wiped prior to the exchange, whatever affection had existed was never to be.
From what those who have researched her program have been able to piece together, she started out as a simple waitress hologram, but through extended use on a 24/7 holodeck, has developed enough sentience to understand her holographic nature, but not enough to start to question the existential matters that eventually form when holograms put serious consideration into their own existence.
She has a number of subroutines which might seem contradictory were they to run simultaneously within her program. She has the capacity as an Emergency Medical Hologram, she can work as a bartender and counselor, and in a pinch, she possesses a Security subroutine to allow her to work as part of a security detail in an emergency.
She spends much of her time as the bartender upon the ship's lounge, but when needed in sickbay, a simple command is all that is necessary to have the computer instantly transport her and upload the Emergency Medical Hologram subroutines.
Between the extended use and multiple subroutines, a number of glitches have begun to make themselves known within her program. For one, the original Ferengi program had followed the standard clothing practices of the species by removing all of her clothing. Although this detail has been corrected, the occasional glitch causes her to become fully naked without warning. Although rare, and apparently associated with deep searches within her memory banks, a significant number of the crew has already had the chance to see her. Thankfully for her sake, her program rejected the modesty subroutines which would normally cause embarrassment.
Her personality also varies notably depending on which subroutine is currently active. While working as a bartender, she appears more submissive, attentive and sometimes playfully flirtatious. While acting as an Emergency Medical Hologram, sympathy shows strongly within her face, but her manner is much more professional, dedicating herself to aiding the injured. When her Security subroutines are active, she's focused like a hawk, no-nonsense and aggressive. Although her memories are unaffected, she does not recognize any inconsistencies within her personality unless they are specifically pointed out, which often causes some form of glitch.