Learn Japanese Chinese Korean

so, as you might know, languages are split up into families (and depicted on a tree) based on roots an the origin of each language i believe. for example: spanish, italian, and french are romance languages. i think neither japanese, chinese nor korean actually fall in the same classification, though i may be wrong. however, these languages are often heavily associated with each other due to some word similarities and language diffusion.
for those of you who are proficient in several languages, does having a basis in a similar family language branch aid in others? asking because my mom is chinese so she said she easily learned japanese (due to kanji). however korean characters look,, different and although there are some similar words, there are just as many borrowed words from english.
would someone who has basis in chinese/japanese learn korean more "efficiently" than someone who only has a basis in english? you can also answer if you're a polyglot with not east asian languages about how you felt in your learning speed!