Should they not be listed as squibs? -- Saxon 20:29, October 19, 2013 (UTC)

They're called Muggles on Pottermore, so I guess not... --Hunnie Bunn (talk) 20:30, October 19, 2013 (UTC)
They are technically squibs; they're non-magical daughters of a witch. Pottermore, however, comes above it all. HarryPotterRules1 (talk) 20:35, October 19, 2013 (UTC)
It would appear that a person without magical ability and with one Muggle parent is a Muggle, not a Squib. -- 1337star (Drop me a line!) 20:51, October 19, 2013 (UTC)
Maybe they're half-sisters or adopted? HanabiHyuuga (talk) 00:51, March 8, 2015 (UTC)HanabiHyuuga

Pottermore refers to Gilderoy as the only magical one of the couple's three children. So they are not half-sibblings.--Rodolphus (talk) 11:03, March 8, 2015 (UTC)