If my employer pays twice a month on th 1st and the 15th. I missed a day of work because I was sick, she deducted 8 hours. So because she is deducting hours, should she add all of the days included in that pay period or is what she is doing right?

First what is your location, the rules and laws in US are different than France.

What is your sick day and leave policy, are you allowed a specific number of sick days and have you used them up already ?

We do not even have a company policy handbook. We are in Texas, USA. It seems to me that if she is going to deduct a day I was out, then shouldn't she include all 11 days for this pay schedule?