Alright... so I thought of something. Our parents are Squibs. Squibs are, per the official cannon of the HP world, the children of wizards who never ended up being able to use magic.
https://www.wizardingworld.com/fact-file/magical-miscellany/squibsThere hasn't been a single mention of our grandparents on either side; wizards live around twice as long as muggles. Unless they died like in the war, why have we never heard anything about them. Why didn't they come by for Christmas? All 4 of our grandparents being dead given how young our parents seem to be is... unlikely.
Could our parents be as far back as what ever created Elliot out of nothing to perform a role and host Helga go back, unable to create anything further than that? Same reason we don't have a sibling, even though mom and dad supposedly wanted one? 