However, in the spin-off series (which aired after the original show ended), it is confirmed that Emily and Alison are married and living together with their twin daughters, Lily and Grace.

So, the "solid feature" you're referring to exists in the spin-off canon, not in the original PLL finale.

As of the main series finale of Pretty Little Liars ("'Til DeAth Do Us PArt," Season 7, Episode 20),