They’re so Vein by Susan Stec

Book 1 in the The Grateful Undead series

What happens to a family of seniors when one gets changed into a HOT vampire chick with a lust for sex and a thirst for blood? Everyone wants to fang up.
There's a hierarchy and rules for immortal beings, and as five senior women go from depends to thongs they tromp they’re newly acquired stiletto's all over them.

“a hilarious and irreverent new twist on the paranormal/vampire romance genre” ~~Amazon review