Well, you don't have to put *I thought* in any more than you would have to put in *she thought* if there is ony one POV character.
i.e.
The man infront me pulled a knife. Legging it would be a good idea I thought
Becomes
The man in front of me pulled a knife. Legging it seemed a good idea.
The man in front of her pulled a knife. Run, she thought in fright.
becomes
The man in front of her pulled a knife. She ran for it, frightened out of her wits.
OK, crappy examples off the top of my head, but I've had it drummed into me that using *I thought* or *she thought* is a bad thing m'kay, and they are generally completely unnecessary words, even more so if there is only one POV( because who else is going to be sharing their thoughts on the page?). Even in multiple POV it is perfectly possible to write without using the words.
One of my tutors even went so far as to say that using the phrase can competely lose a readers immersion, as if you don't use *I thought* the sentence reads in the readers head as though they are thinking it, and it becomes more intimate and immediate, allowing them to connect much more easily with your character.
Just type it as though she is talking to herself in her head - do you ever add the tag I thought when you do that?