That's not how I see it... If I don't leave a message, it's usually because I didn't have anything special to say, or I know I will be unavailable later. If I have something special to say, I'll leave a message, if nothing else to say, call me.
But you know what her particular pattern is. Does she usually leave a message? Would the two of you normally call back if you saw the other had called? Should you be that available in this new situation?
Let her keep reaching out to you. At the very most, use Zues option #2.
M 16 yrs, WH62, P54 3 adult blended kids EA 11/13, BD1 6/14 PA fall 14, BD2 2/15 Piecing 2015, BD3 12/15 Separated 4/16 WH moved OW in 5/16 Divorced 6/15/17
Zues