Just to clarify what Thomas said, assuming that you have managed to set up an HTML "formatted content" signature set, it will only be used if the message you send uses formatted content itself (bold text, coloured text, different fonts, etc) or the Rich Text tickbox near the subject line is ticked by your wife. Otherwise Pegasus thinks you are sending a plain text message and uses the basic version of the signature.
Just to clarify what Thomas said, assuming that you have managed to set up an HTML "formatted content" signature set, it will only be used if the message you send uses formatted content itself (bold text, coloured text, different fonts, etc) or the Rich Text tickbox near the subject line is ticked by your wife. Otherwise Pegasus thinks you are sending a plain text message and uses the basic version of the signature.