Do some reverse phone lookups using the number. Some of the background check services can give info based on only phone number.

As the others say, play this close to your vest. The more you let her know about what you know, the further into hiding she'll take it.

M(53), W(54),D(19)
M-23, T-25 Bomb Drop - Dec.23, 2017
Ring and Piecing since March 2018