создайте элемент LineString с теми же координатами (долгота, широта, высота), что и ваши точки.
<Folder>
<description>Frankie likes walking and stopping</description>
<Placemark id="track1">
<name>frankies path</name>
<LineString>
<coordinates>-46.67,-23.58,100 -46.754,-23.666,100 -46.6616,-23.5632,100 </coordinates>
</LineString>
</Placemark>
<Placemark>
<name> 2012-05-31 17:23:09</name>
<description> Stop TIME: 19:25:20 Source: network</description>
<Point>
<coordinates>-46.67,-23.58,100 </coordinates>
</Point>
</Placemark>
<Placemark>
<name> 2012-05-31 17:23:09</name>
<description> Stop TIME: 03:01:59 Source: gps</description>
<Point>
<coordinates>-46.754,-23.666,100 </coordinates>
</Point>
</Placemark>
<Placemark>
<name> 2012-05-31 17:23:09</name>
<description> Stop TIME: 02:26:13 Source: network</description>
<Point>
<coordinates>-46.6616,-23.5632,100 </coordinates>
</Point>
</Placemark>
</Folder>