what are the results of being accused of indecensy and sexual contact with a child?

If you were within three years of age of each other, then consent would be an issue because Texas has what is called 'Romeo/Juliette' law.  This defense provides that if the two parties are within three years of age of each other and the sexual acts were consensual... then it's a defense.
From the looks of your question, you are more than three years older than her, which means this defense will not be avaible to you because she was not over the age of consent.
You're in a pickle if the facts are true.  You can be charged in a different indictment for each time that the two of you engaged in sexual relations.  If any part of your body (sexual organ, finger, etc) penetrated her vagina, then it's a first degree felony with a range of punishment of 5-99 years in prison.   Sorry to sound graphic... that's just the terminology in the law.  If you only touched her breasts or private areas, but no penetration, you could be looking at 2-20 years.  Each offense would require you to register as a sex offender. 
Overall, Texas has some of the toughest sexual offense laws in the country.  That's the bad news...there is a possible silver lining.  If you have never been convicted of a felony, you could be probation eligible for these offenses.  This means that even if you are found guilty, then you could still avoid prison.  You could also petition the court at a later date to lift the registration requirement. 
It is possible the state will not go forward on the case.  Much depends on the strength of the case against you, how they feel about you, and how the victim would like to proceed.  So.... right now, no more communication with the girl.  If you keep seeing her, it will only aggravate and encourage her parents to complain about you more.  You want to be out of sight, and out of mind.  Second, get off Facebook or any other social media outlets.  Everything you say on there right now is subject to scrutiny by law enforcement.  Even if you have made your comments 'private' to one of your closest friends, the government can still potentially get a warrant and obtain your records.  They actually offer classes at every domestic violence/law enforcement seminar on how to do this.  So... don't give them any more ammo:  like pictures of you with other girls that might look young(they will say your are predator based on patterns), pictures of marijuana leaves (because they will say you're a druggie), or pictures of you holding a gun (because they will turn you into an abuser too).  Basically, when you hear the phrase 'right to remain silent', that includes any social medial too.  The cops may want to visit with you.  I CANNOT STRESS ENOUGH.... TAKE AN ATTORNEY WITH YOU IF YOU GO.  Again, because sexual assault is such an issue, they teach officers at specialized schools and seminars on how to pull details out of you to make it seem worse than it was.  You do not need to be in a room alone with them.  If they are going to accuse you of something this horrible, make them do their job.  You don't need to give them any extra ammo to shoot you with. 
Many parents of victims this age just really want the whole thing to go away and they do not want to put their children through this type of scrutiny.  So keep these parents in this mode (assuming they are). The best option is to lay low and avoid contact with her or anyone close to her.  Sometimes just laying low and moving on is enough for the case to float by.  However, you still need to visit with a couple of criminal defense attorneys... so that you are prepared if/when the charges move forward.