I have a friend who is the seller and I am the buyer in our business. I call her Auntie even though she is only 13 years older than me. She used to get up late and never do exercise. But now, when I get up at 5:30 and I am proud, she gets up at 4. When I walk, she runs. When I waste time, she is learning new things. And when I am lazy while discipline, she go straight ahead without any gap for years. I don't have a clue how she can be wonderful like that but it is a motivation for me. I will go the extra mile.

My business partner, who is also my friend is the seller and I am the buyer. I call her Auntie even though she is only 13 years older than me. She used to get up late and never to exercise. But now, while I feel proud when I get up at 5:30 a.m. she gets up at 4 a.m.. When I walk, she runs, when I waste my time, she learns new things... And when I am lazy sometimes even though I try to be more disciplined, she manages to work all year long without a single break (I modified your sentence according to what I could understand because it was quite confusing, let me know if that's what you actually meant). I don't have a clue as to how she manages to be so amazing but it is a source of motivation for me. I will go the extra mile to reach my goals.

I have a friend who handles sales, while I handle purchases, for our business. I call her "Auntie" though she is only 13 years my senior. Formerly, she woke up late and never exercised. Now she wakes at just 4:00, while I feel pleased if up by 5:30. I walk. She runs. I waste of time. She learns new things. And, whereas I slack on self-discipline, she forges forward for years on end. I don't have a clue how she manages to be so exemplary but she serves as a model for me. I must go the extra mile. Your first sentence is hard to understand. It sounds like you are selling your business and you have found a buyer. This, however, clearly is not what you mean to say. "Auntie" must be in quotes since you are talking about it as a name. Don't be afraid of very short sentences (like "I walk."). They can have a powerful impact. Your writing will improve if you discover and use interesting verbs. You depend too much on the boring verbs "to be", "to have", "to get", and "to do".

I have a colleague in our business who is the seller and I am the buyer. She is also my friend. I call her Auntie even though she is only 13 years older than me. She used to get up late and never do any exercise. But now, when I get up at 5:30 and I feel proud, she gets up at 4. When I walk, she runs. When I waste time, she learns new things... and when I am lazy sometimes, lacking discipline, she continues without any gap for years. I don't have a clue as to how she can be wonderful like that but it is good motivation for me. I will go the extra mile.