Measure the leaf !! It should be about 1/4 in. tall !! Fakes are larger !! I see no problem with it being authentic !! Many of these had no named pattern !! Made between 1891 and 1921 !!

https://www.collectorsweekly.com/asian/nippon-porcelain

You might look through the ones listed in the linkand get an idea of what it would bring if sold !! Nippon is not as popular or as pricey as it once was !! And it is not hard to find !! Ebay closed and sold auctions are another option for prices !!
No way to assign a value because an item is only worth what someone is willing to pay !! Asking price and getting price can be very different !!