Chameleon's tongue not extending all the way...?

I fed my chameleon two nights ago and noticed that she didn't extend her tongue all the way out when reaching for the cricket, like she normally does.

At first I thought nothing of it but it happened all the way through her feeding. It happened again last night.

This is a first in the 7 months that I've had her.

Is this normal or do I need to worry? Am I doing something wrong, is there an perhaps an underlining issue and what can I do to sort it out?

Thanks!