My mind jumped to Lusha / Луша. So I googled "Луша Луиза" and it came up with some kind of small Russian series or franchise of some kind called Dnevnik Luizy Lozhkinoi (Diary of
Luiza Lozhkina) and it appears that the titular character is called Lusha for short. I don't think Lusya is such a stretch from Lusha at all.
http://beremennost.net/content/luizahttp://kakzovut.ru/names/luiza.html
On these Russian sites I found:
Лиза /
LizaЛуизка / Luizka
Иза /
Iza
Longer pet forms
Луизочка / Luizochka
Луизонька / Luizonka
I've looked through a few Russian sites and the most prominent nicknames seem to be Luizka and
Liza. I understand not all of the nicknames listed on the second site are Russian but I saw Lucha / Луча, its similarity to luch / луч made it quite cute.
This message was edited 11/20/2016, 1:28 PM