Liu Zitong sounds good. Catalpa and Paulownia are two kinds of trees, but Zigong and Catalpa have the meaning of coffin, which is unlucky.
Liu Ruotong-If you take it literally, Tung refers to the Chinese parasol tree, which is ancient. Literally means "like a buttonwood tree".
I don't know why you are so fond of the word child. Personally, I think the word child is more common as a name, but it is not particularly brilliant.
I think maybe we can change the third name to "Ruotong". Wang Anshi has a famous poem, "Thousands of families are always exchanging new peaches for old ones." Every household is bathed in the morning sun in early spring. I think the word "pupil" is beautiful, full of vigor and vitality, and suitable for girls.