By Abigail O’Leary A US ballerina who was arrested in Russia has spoken out about the terrible conditions she’s facing in jail. She says she can only shower once a week, it’s very cold, and the lights are on all the time. Ksenia Karelina, who used to be a ballerina but now works at a spa in California, was arrested while going to Russia from Los Angeles. She is said to have given $51 to a charity that helps Ukraine. Her boyfriend, Chris Van Heerden, said they had been on holiday in Istanbul when Karelina started missing home. To cheer her up, he bought her tickets to Russia, and she let him kn…