YOU SAID:

I like your mother she's very nice.

INTO JAPANESE

私はあなたのお母さんがとても素敵なのが好きです。

BACK INTO ENGLISH

I like that your mother is very nice.

INTO JAPANESE

私はあなたのお母さんがとても素敵であるのが好きです。

BACK INTO ENGLISH

I like that your mother is very nice.