I inherited a small vase jade in color handles with raised markings. Painted on the body, two flowers and one bud (lily) and leaves. On opposite side is one bud with leaves. The bottom says royal moriye nippon looking for its value

Nippon vases were made in Japan, probably around l850, were manufactured and the market was flooded, nor more were made. If you have an actual Nippon vase, hand painted, which makes it more valuable, could be worth upwards of $1000. I don't know what you have, but as a rough guess only having seen actual vases such as this. Of course you could have a knock off, but I can't see it, so can't say for sure.

So how do I know if it is truly an original?

You could take it to a Noritake dealership, phone first to ask if they will, or an antique dealer in your area.