I know this is evading the actual question, but I have a soft spot for cliche sayings that have longer versions that flip them on their heads. And my favorite of those is:

"The blood of the covenant is thicker than the water of the womb."

Because so many cishets will tell you how family is strong and forever, and so many queer people can testify, either firsthand or secondhand, to how that's really not as true as the others think. Chosen family is choosing to be there. They're not there out of obligation or duress (until they snap and disown you), but because they want to be -- because they genuinely care.