Yes, he would be categorized as a first offender. Thus, if he does not have any prior felony convictions he could be eligible for community supervision. Regardless, the other allegation may be used against him for punishment if the prosecutor believes it happened. If he had a prior conviction for this type of offense he may have been facing life in prison.
It is difficult to determine what the man will be facing this time because you did not state if he has been charged with a crime. Also, you do not state if this just happened once or has it been happening over a period of time. It is pertinent to know what the child's age was at the time of this incident. For example, if he is charged with sexual assault of a child and the child is under the age of six he would be facing 25 years to life.
I am sure this may create more questions, but the law of sexual assault of a child is complicated and has signficantly changed recently.
Mr. Martinez is correct - the man will be considered a first offender. However, the extraneous offense that was not pursued can be used if the man is found guilty to encourage the sentencing authority to make his punishment harsher.
If he only touched your granddaughter but did not penetrate her (in even the slightest amt with anything), then it is a lesser offense. If you granddaughter was under 14 (even by a day), then the punishment is greater (as long as the offender is not within 3 years of her age.)