How much light was coming through your window?
If there wasn't much light coming through then that will be the reason they've become leggy and weak. When plants aren't recieving enough light they stretch for it and just shoot up as tall as they can.

Just keep them supported and if they recieve enough light from now on they'll strengthen up and they'll be fine.
GTC21 Reviewed by GTC21 on . please help Hello, I planted 2 seeds in my kitchen by a window just for the hell of it b4 I left on a weeks vacation. When I returned I found 2 plants about 5 to 6 inches tall, each with 2 round leaves and 2 jagged ones a little higher up the stem. So I did what any good pothead would do and I went out and bought 2 85 watt flouros each giving off 1600 lumens, some good soil, peat moss, and some new pots with good drainage. They are now almost 2 weeks old and are about 6 to 8 inches tall and are each Rating: 5