I think that the availability of dlc can be checked in the online version of the game that the developer gives to his patreons. Upload your save there and see if there is additional content or not.
Gym quest for Mother character is broken RN. save the game locally BEFORE u do the event and take the save file to an editing site, I used "saveeditor.online" not "saveeditoronline", after loading the save file onto the site you can search for "quest", then find the "momMainquest" and change the "1" to a "2". then click the download button, then load the save and it should have progressed the quest.