Yeah, they're completely different generations. Zula would be 40 when Olivia was born. SM's timeline dates Rescue - the last time we saw Zula? - as 2145, a good decade before Olivia is born too. So yeah, I imagine they'd have to bring in some cryosleep shenanigans to keep them reasonably close in age. And it's the Alien series so that's not out of left-field.