Just hand her the letter. No need to make a show of it.

"This came for you" (And hand it to her).

As if it was a letter from her dentist. Who cares what it is anyways right?

H 37
W 31
S 2

T: 7
M: 4

BD 12/18
Separated 2/19
Living back together 04/06/2019
W Moved out again 07/15/2019