A client has set up her @Gmail.com signature on a desktop PC, and it displays fine in a desktop browser.
However, when she uses her native iPad browser, it does not append or appear when composing a new email.
When using a mobile web browser, Gmail detects that and offers to use a "mobile signature" instead of the desktop signature. What might be happening here is that she has the switch "on" for the mobile signature, but the mobile signature is blank.
To use the mobile signature: