"Who does she like?"
Translation:Koho má ráda?
I deleted the non-sensical and too much heated discussion.
Anyone who feels that "whom" is required here please do check the ngrams first https://books.google.com/ngrams/graph?content=who+do+you+like%2Cwhom+do+you+like&case_insensitive=on&year_start=1800&year_end=2000&corpus=15&smoothing=3&share=&direct_url=t4%3B%2Cwho%20do%20you%20like%3B%2Cc0%3B%2Cs0%3B%3BWho%20do%20you%20like%3B%2Cc0%3B%3Bwho%20do%20you%20like%3B%2Cc0%3B.t4%3B%2Cwhom%20do%20you%20like%3B%2Cc0%3B%2Cs0%3B%3BWhom%20do%20you%20like%3B%2Cc0%3B%3Bwhom%20do%20you%20like%3B%2Cc0
"WHO" is the most common variant here even in written English. "WHOM" remains to be correct, but its use is declining strongly and is almost absent from spoken English.
WHO will be kept in this and some other sentences.
Se is a part of the verb líbit se. Se makes it a reflexive verb, somewhat similar to English '-self' like 'to wash oneself', German 'sich' 'sich wundern' or French 'se' 'se laver'.
You use líbit se with dative case like this: líbit + se + dat + sth/sb. The dative explains who is the person who likes sth/sb. In this case, we use jí (dative form of ona.)
Note, that there is a slight difference in meaning - mít rád/ráda implies 'liking sth/sb over a longer period of time' while líbit se is more about 'perceiving sth/sb positively.'
Oh, I am afraid it does happen in Polish and Russian as well. Although, in Polish, they use 'się': 'nazywać się' or 'uśmiechać się'. Dative form of 'ona' in Polish is 'jej'. In Russian, they use 'sya' and 'sebya', '-ся' and 'себя́' and other forms; 'нра́виться' = 'like'. Dative form of 'ona' in Russian is 'ей'.