how old is too old to bring mommy into things?

I don't have a car and me and my friend wanted to go a birthday party, so her mom let me drive her car.  I was running a little late from a different friends house and her mom had to wait 12 min.  for me.  I said sorry and told her what happened.  She was it was fine people run late and then went on to say that her daughter could be late for 12 days because I was 12 min. late. 

I drive her daughter to school 3 days a week.  There house is out of way and don't ask for gas money because her mom gave me rides to dog training and then I lived 2 blocks away now its more than a mile. Then she would say leaving and I would wait any where from 15 min to over an hour for a 2 min drive outside.  Her daughter is almost never waiting for me.  I have to send a text message and wait for her to get and then walk outside.  Witch takes a few min.  Her mom went on to say that you yell at her daughter for being late.  I went on to say I have told her 2 times to be ready and waiting.  The first time I was a few min late and said will you where late and I told her I have wait for over an hour outside for you once so a few min really. 

Her mom went on to make it sound like I yell at her ever time.  I have been coming on time for about about the last 2 months.  1 or 2 time I got stop as was leaving by dad because I drive his car.  But I think if she had a problem she should of said something to me and not have her mom.  What we are 19 now and going to be leaving the home on are own in less than a year and she had to have her mom yell at me.  I was like really are we 12 again.

This is not her mom has stepped in on something.  Her mom has also tried to tell me who I could be friends with because her daughter did not tell all of story to her mom making someone look like a really jerk.  When it was a little mean but in her best interest.  And she blew the story wait out than what it is and added things.  Making seem like she was this little sweet thing getting picked on.  I was likes not the whole story and my friends are my friends. She does not have to be friends with them.

She has never said one word to me about anything.  I just want to know how old is too old to have mommy getting into things.  I don't have my mom step in when I have problems with people, I may tell my mom about them just to tell some one but my mom has not stepped in years.  Not saying anything to my friends.