Is Rabbi Moshe Yirmiyahu Gershon Hakohen Rappaport, Rosh Metivta in Vienna supposed to be Moses Cohen Rapa ?
We need actual evidence for the children, because there was a lot of misinformation published in the late 19th century (as discussed by Wachstein) and so it isn't enough just to refer to someone's attempt at a family tree without historical sources.
In Anaf Eitz Avot written by Shmuel Zanvel Kahana in 1903 (www.hebrewbooks.org/6392). He mentions on page 25 that Moshe Yirmiyah was a son of Simcha author of Kol Simcha. He quotes Yosef Kohen Tzedek in his book Dor Yesharim (https://www.nli.org.il/en/books/NNL_ALEPH001971683/NLI) written in 1898.
On page 6 foote note #3 he mentions that Moshe Yirmiyah Gershon was son of Simcha the author of Kol Simcha.