Body Temp

I'm wondering, can someone's "normal" body temperature change? Take me, for example: on a typical day my body temp is 97.6. On any given day, and at most any time of day, if I take my temp this is the reading I'll get. If my temp gets into the upper 98's even I notice that and typically don't feel great. So, is it possible that one day my "normal" body temp will just change to, say, 98.4? And from then on that would be a "normal" reading for me?

What would make me ask such a strange question? Emily, of course! LOL I've taken her temp countless times over the last 16mos. And the times her temp was "normal" it was in the upper 97's, just like me (and both her brothers). Well, earlier this month I stated noticing her feeling warmer~sometimes late morning, late afternoon, or even in the evening. It'll be in the low 99s, but then a couple hours later is back into the 98's~which would still be high for her normally~and NEVER in the 97's. Other than feeling warm, she's typically fine. But some days when her temp is higher I have a difficult time getting her to take her afternoon nap~even though it's obvious she needs one.

It's just weird! LOL I thought maybe it was just the thermometer, so I took the boys' temp with it. Sure enough I got typical readings on them, but Em's was still higher. So, is it possible that her normal body temp has just risen for some reason?