A lot of the names that are not flowes or jewels, like Dora
, and Tanta, are not supposed to mean anything in the hobbits' language. It was just something they used for so long because they probably liked it.
I'm guessing Firiel (the name of Elanor
's daughter) was used because of Elvish influence. There was at least one other Firiel - a woman of Gondor.
The three Daisys were: Sam
's sister, one of his daughters, and one of Frodo
's cousins. May
was the name of one of Sam
's other sisters, as well as the name of his father's sister. (Marigold
was his third sister.)
Supposedly, the lobelia flower symbolized ill will in the Victorian language of flowers. This probably inspired Tolkien to use it on a bad-tempered character.
Pimpernel was a Took as well. Pippin
's three sisters were Pearl
, Pimpernel, and Pervinca. Pippin
was the youngest and the only boy. And yes, Eglantine
did have at least a son (who inherited his father's title), but Tolkien never said his name.