It can get Shelly Estrella's skin?
In order to have Shelly star You must Create an account during its Global launch in December of the Global launch of Brawl Stars Android by Supercell.
What I mean, if you didn't create an account during PRE-REGISTRATION You cannot currently obtain it.
Regretting to say this I will leave you a little happier knowing that we have guides to get gems and Brawlers.