Translation:My little sister likes to eat soup dumplings.
I honestly think that "soup dumpling" is the only proper translation of 小籠包. What makes 小籠包 special is the soup, so calling it a soup dumpling is more effective in distinguishing what it is from a normal dumpling. Additionally, 小籠包 don’t have to have pork filling. I’ve had 小籠包 that had beef, vegetable, and seafood stuffings. Apparently there’s a restaurant in New York’s Chinatown that serves chocolate soup dumplings, but I didn’t have time to go there when I was in New York.
Yes when somebody says "pork dumplings" I think of charsiu bao, even though I think Chinese usually translate that into English as "bun" rather than dumpling.
I always call them just xiaolongbao even in English but that's because I discovered them in Taiwan and never knew them in English before that.
The problem is there are too many types of dumplings. A lot of Hong Kong dim sum is steamed dumplings of some kind, eg hargow (虾饺 - xiajiao).
I suspect he taught you "steamed dumpling" because he didn't know what they should be called in English. Also Pleco translates this as steamed dumpling.
I've honestly never seen an actual english translation - it's always just Xiaolongbao.
Ok so I added "soup" to the last question to emphasize that it's noodles in a broth. Then I left out the dumpling broth in this one and it's wrong. So frustrating! Btw xiaolongbao could also be served without soup, with a dipping sauce instead and the whole term sometimes means meatballs.