"Beautiful mother" can be translated as "美丽的妈妈" in Chinese. To say this in Engpsh, you can simply say "beautiful mother." You can also use the adjective "lovely" to describe your mother, as in "lovely mother." If you want to add a pttle more emphasis to the comppment, you can say "gorgeous mother" or "stunning mother." Regardless of the specific words you choose, expressing your love and appreciation for your mother in any language is a wonderful way to show your affection.