Names for Female Sisters

Hello Everyone! I am hoping for assistance translating two female names (sisters) into Quenya. I am toying with the idea of twin sisters with names in that sweet spot of similar, just not too similar.

The first name, intended to mean "daughter of starlight", I believe comes out as Ilmariel.

The second name, "daughter of moonlight", seems to be Isilmiel. I think this is correct, but in looking at alternate choices I thought of going for "maiden of moonlight" which seems to be Isilmwen. The "mw" in the name seems a bit off to me. Since Quenya doesn't mutate like Sindarin, would leaving the "mw" be correct? Or is there a better/alternate way to construct this name?

As a related side question, I read through previous discussions on the site for help (such as this one: www.elfdict.com) and noticed name formations such as Calwen(dë). Do the parentheses in the translation simply denote the dropped dë from -wendë to show how the name is formed? Or do they suggest these dropped letters are sometimes retained in a name, making Calwendë an unusual but "correct" name?

Thank you for your help!

The name Isilmien would work for maiden of moonlight, as in Arien (day-maiden).

I believe (-wende) is the Quenya and (-wen) is the Sindarin, but I'm not sure.

Per Ambarkas' recommendation, Isilmien might work for the name of the second sister. Whereas Ilmarien would suit the first.

As for the name Calwen(dë), I believe the -dë is in parenthesis to denote the longer form of the name, whereas Calwen would be the shorter (perhaps diminutive) version. This can also be seen in the name Alcarinquë ("Glorious"), which is also simply called Alcarin.