Thranduil alternate name + matching queen name

Ara- / aran (king) + tuil (spring)

= Arantuil (King (of) Spring) / Aranatuil (King of Spring)

AND

danna (autumn) + rían (queen)

= Dannarían (Queen (of) Autumn)

Mae govannen!

Arantuil would mutate to Aranduil. If you want a "t" in the name, you could always switch the order to Tuilaran. Elves do not use "of" as an article in names, so Aranatuil would not work.

The word danna means fall as in "the rock fell", not as in "autumn". Instead, you would use the word iavas. That would lead to a name like Iavathrían for "Queen of Autumn".

As always, I recommend a second opinion!