SWEET かわいらしい、優しい

If someone (especially a baby or child) or something is sweet, they are attractive or easy to love. To be sweet is also to be kind or considerate.
sweet とは、人（特に赤ちゃんや子ども）やものが魅力的で、愛すべき様子である、という意味です。sweet には、優しい、思いやりのある、という意味もあります。

What a sweet little child! She looks just like an angel!
Wendy's 5-year-old has such a sweet face, it's hard to believe he could be so naughty.
My boyfriend is very sweet. He's always surprising me with flowers and small gifts.
Your daughter was very sweet to my little boy. She read to him all afternoon, just like a big sister.
(on the phone with a sick friend)
a: Well, I'd better let you get back to bed. I'm glad you're feeling better.
b: Thanks. It was sweet of you to call.

英会話レッスン ... and so are you!