FWIW, in Linux, Sigil (qtwebkit) seems to use the "Times" family in the BV, so you can control the font Sigil uses in the BV using an alias, something like this in ~/.fonts.conf:
Code:
<?xml version='1.0'?>
<!DOCTYPE fontconfig SYSTEM 'fonts.dtd'>
<fontconfig>
<alias binding="same">
<family>Times</family>
<accept>
<family>DejaVu Sans</family>
</accept>
</alias>
</fontconfig>
here I made it use the "DejaVu Sans" family, use the font you prefer (to get the exact font names, just look at the font settings dialogue in your DE (KDE, GNOME... etc)).
N.B. If you use KDE, ~/.fonts.conf probably already exists, so just add this part before the closing
</fontconfig> at the bottom of the file:
Code:
<alias binding="same">
<family>Times</family>
<accept>
<family>DejaVu Sans</family>
</accept>
</alias>
This is on Fedora Rawhide, Sigil built locally from source against Qt 4.8.0.