Yes, it is a little strange. It certainly doesn't look like an English girl's name. But that isn't a problem at all : if that's the way that your Manchu name sounds, then it's absolutely fine to call yourself that. It's helpful for non-Chinese people like us if you spell your name in English characters, but there is no reason why you have to give yourself an actual English name. If you want to make it look a little bit more like a typical girl's name, you could change the spelling to 'Sula' if you like. In the majority of western countries, the final 'a' suggests a feminine name. Or you can leave it as it is, if you think that the current spelling is the closest to your real name. You should be proud of your cultural heritage and proud of your own name. You really needn't worry whether it's an English name or not.

I've never heard the name "Suler" before, however, it's perfectly normal for non-English speakers to continue using their name from their native language. English is an extremely popular second language, so a non-English name is expected. Most names used by native English speakers are not of English origin, and native speakers have no idea what they mean in the original language.

Thank all of you guys! I've learned more.

I have never heard or seen anyone use 'Suler' as a name, although it could be used as a Surname.