You can add this code to your theme’s style.css file to override default LatePoint font family, replace YOUR_FONT_FAMILY with the font family you want to use:
.latepoint-w { font-family: YOUR_FONT_FAMILY!important; }
.latepoint-lightbox-v2 h1,
.latepoint-lightbox-v2 h2,
.latepoint-lightbox-v2 h3,
.latepoint-lightbox-v2 h4,
.latepoint-lightbox-v2 h5,
.latepoint-lightbox-v2 h6 { font-family: YOUR_FONT_FAMILY!important; }