Yes but it doesn't sound right. It would sound better if phrased Lassitude overcame her at night.
my own lassitude has been the results of finishing my homework
The knight rode of valiantly into the night.
I had the most beautiful night yesterday and I didn't want it to end. Outgoing people are usually more at ease during night time.
I was lassitude when I stayed up all night to finish my homework.
After a day of difficult and tedious work, my body was plagued with unceasingly torturous lassitude, so naturally, I was eager to relinquish my consciousness in a divine, fluffy white bed. Is that...