is Mercy Dead?

So an idea/theory popped into my head. fter seeing Mercys "no Pulse" emote i had to stop and think, is she saying she has no pulse?.

it made me think about a few other lines. mainly an interaction with Mei, where they talk about each others lack of aging. for those that dont know, Mei was Cryogenically frozen by being put in cryostasis. this happened before Overwatch was even established. but why would mercy inquire about age?

Mei: "Doctor Ziegler, you haven't aged since the last time I saw you. Mercy: "And neither have you, Mei."

if we consider the last time Mei saw her was prior to Cryostasis. and thus before overwatch then we can say that some time has passed.

Mei has a reason, Mercy: "Mei, you haven't aged a single day. What's your secret?" Mei: "Cryostatis. but i do not recommend it"

but whats mercys reason for not "aging a day" even those actors who look like they did like 40 years ago still show some signs of aging or change,