Not sure how large these get, believe mine got to be about 5 inches across. I'm also not sure how these particular ones breed.
Reproduction of Anemones:
Spans the entire gamut, sexual and asexual. New individuals may form from a piece torn off during locomotion or trauma, by longitudinal or transverse fission.
Sea anemones may be separate sexes or hermaphroditic. If same ---, generally eggs and sperm tend to be produced at different times. Fertilization and some development may occur within the body cavity or not. Typically, anemone larvae have a planktonic developmental phase before settling.
Thomas