母(はは) hahaは wa年(ねん)齢(れい) nenreiより yori若(わか)く() wakaku見(み)え()ま()す() miemasu。 My mother looks younger than her age. Literal Mother [topic-は] age [than-より] young-[adverb-く] appears-[polite-ます] 年齢より若く見える = 'appears younger than (her) age.' 見える here is 'to appear/look' (not 'to be visible'). より marks the comparison. 若く is the adverbial form of 若い. family~より (comparative)
母(はは) hahaは wa年(ねん)齢(れい) nenreiより yori若(わか)く() wakaku見(み)え()ま()す() miemasu。 My mother looks younger than her age. Literal Mother [topic-は] age [than-より] young-[adverb-く] appears-[polite-ます] 年齢より若く見える = 'appears younger than (her) age.' 見える here is 'to appear/look' (not 'to be visible'). より marks the comparison. 若く is the adverbial form of 若い. family~より (comparative)