What theme are you using? Kubrick is the “DEFAULT” theme. It is also the theme that is listed next to your name and blog name, on the Manage part of the Admin Panel, as though it were your own theme. In the stylesheet for Kubrick, go down not too far, until you reach
`/* Begin Typography & Colors */
body {
font-size: 72%; /* Resets 1em to 12px ? */
font-family: “Times New Roman” ‘Lucida Grande’, Tahoma, Verdana, Arial, Sans-Serif;
background-color: #d5d6d7 /* soft gray */;
color: #333;
text-align: center;
}
‘
The default Kubrick font-size is somewhat smaller than 72%. That’s the change I’ve made. All you need to do is to make this amount larger. Then all the other “size” instructions change in sync with this basic size percentage. That is, sizes stated as 1.2 em or 4 em or .9 em are all proportional to the percentage you state in this first “body” style.
It’s “sister” not “brother,” by the way.