Dionne Tyrol

Dionne is the half-human/half-Cylon hybrid daughter of Galen Tyrol and Sharon "Boomer" Valerii. She solely existed in the projection created and utilized by Boomer, and was originally made as, at a time when Boomer and Galen both thought themselves to be human, and were in a relationship and planning to settle down, Boomer wished to have some form of child with Galen. In reality, Dionne does not physically exist, as Galen and Boomer's relationship broke down.

When Boomer came to The Fleet and was subsequently imprisoned in Galactica's brig, she showed Galen the projection of the house on Picon, and Galen was only truely taken by the illusion in when he saw Dionne's image. In reality, Boomer had used the projection to manipulate and gain Galen's trust; as part of her mission to kidnap Hera Agathon.

When Galen was informed of Boomer's duplicity shortly after her departure, he was reduced to a state of denial and (apparently) went back into the projection on his own. He no trace of either Boomer or Dionne. (Someone to Watch Over Me).