It's hard to say. Some people seem to know it and some don't. Doesn't seem to make a difference though since DC doesn't even let PG near the Superman Family even though they fixed her origin as a cousin of the alt/universe Kal. Seriously, Allura is a alternate-universe doppleganger of her own mother who died when Krypton blew up and there has not only been zero interaction between them but we've never seen PG be even curious about it all.