That goo just latched onto the solid they found first, without even knowing what gender is.
Could Quicksilver Harry and Quicksilver Tom talk to the rest of the quicksilver on planet, because creating a massive shift in the existence of thousands of tons of quicksilver matter without permission from that quicksilver matter is like Colonel sterilizing the genetically damaged by the millions after World War III...
Not only did they take what they got and stuck to it but 1,000,000 percent more Quicksilver matter was tricked into being the ship when it equally could have wanted to be "people" if it had had been told how much better it was to be people than a hulk of metal hurling through space.
Is it more substantial to be a person or be the ship?
Why be less substantial?
It's been a very long time since I saw this last, but the Quicksilver was given a choice, despite having no method to make an informed choice, or even language, or it was all frogmarched into a change in existence so absolute that it's comparable to death.
And even then, they didn't chose gender, and we are not aware if the quicksilver played swapsies with their identities until everyone was happy... But if that was true, then you would expect that there would be duplicates of some of the crewmen.
Are the Delaney sisters flesh and blood or quicksilver?