Am I disqualified from adopting?

Hi, I have an unusual situation (?) and I am wondering if it is possible for me to adopt. I am a single woman, 37, employed full time and I make a little over $50,000 per year. I have a biological daughter who is 15. I don't smoke, or do drugs (prescription or otherwise). I don't care for alcohol. I am involved in a church, and I regularly volunteer. For 10 years I have had a desire to adopt older children (high school age). I didn't do it because I was married and did not have the support of my husband. We separated in 2004 and our divorce was final in 2005. At the time of our divorce I had financial problems. My daughters father refused to help (and never has). If it weren't for the help of my parents who thankfully live in the same city I don't know what we would have done. Thankfully my income has increased and I am now in a better financial position. So here is my unusual situation... Because of my divorce for two years (2004-2005) I had to rely very heavily on my parents for help with my daughter. I was barely paying my bills but still managed to keep my daughter in private school. I chose to voluntarily surrender my car so that I could use my car payment to keep her in private school. I bought a used car with no payment instead. I had to take a job with an extremely long commute so that I could earn more. It started off with me dropping my daughter off at school in the morning and going to work. My parents would pick her up from school and help her with her homework and have dinner with her. I would then pick her up at 9pm on my way home (sometimes as late as 10pm). This was very tiresome for her, and she would fall asleep in school. So then we decided that if she fell asleep before I got there that she would just stay there for the night. Things improved for me a great deal financially and I was able to move nearby to work. At that time I had my daughter full time with me. At that time my daughter was in public school (it was a fantastic school). After school she would be at the boys and girls club. We would get home at 6pm and have nice normal evenings. This went on for just over 2 years . Then I experienced a financial emergency (my employer committed suicide) and had to move back to near my parents into a house shared with roommates. The roommates claimed to be church-goers but once I moved in it was apparent that they were not people that I wanted my child to be around (bad lifestyle choices). Because of my financial situation I was not in a position to move out quickly so my daughter stayed even more at my parents house. I didn't mind because I have great parents, and I was close enough to see my child whenever I wasn't working. We even converted the spare room at my parents house into a room for my daughter. They also began paying for her to go back to private school. Since I was trying to get back on my feet financially my parents had the suggestion of putting my daughter on their health insurance so that I could save money and because their insurance also offered orthodontic. Of course, it is only legal to do that if they had guardianship. After much discussion I decided to voluntarily sign guardianship papers with them with the agreement that it would be temporary until I got back on my feet. The guardianship would allow them to also claim her on their taxes which seemed only fair to me since they were already paying so much for private school. I got back on my feet (2010 to present) but my daughter had become very accustomed to the financial level that my parents live at and does not want to officially live with me. Their income is more than 4 times my income. They live in a very large house with a pool. I live in a two bedroom house in a less affluent neighborhood. My daughter goes to private school with children that are quite well off and my daughter is embarrassed to invite her friends to my house (even though my house is really cute for being small). My daughter spends 2-3 nights a week at my house, but because of her feelings of embarrassment towards my "financial inferiority" we've decided to leave the guardianship in place at her request. My daughter's best friend spent some time in foster care and is now living with her birth mother. Her birth mother has a felony record and is unable to find a job in this economy and has also struggled with drug dependency. They lost their house and are staying with family friends a couple hours from where we live. My daughter's friend has expressed to me repeatedly that she wished that her mom was like me. I've often wished to take her in, but naturally she wants to be with her mom (though I have made sure that she knows that she can call me for help any time if she wants). I've been feeling pretty inferior compared to my parents because I can't afford a house with a pool or $600 a month for private school. But I do make a lot more than minimum wage, and I have money left over after paying bills and am able to do things like pay for prom, etc. My rent is only 25% of my income. Statements from my daughters friend made me realize that there are kids out there who wouldn't mind having me for a parent. I had thought I'd have to wait a few more years and buy a house before looking into adoption, but after reading about adoption requirements I see that I do not have to be as wealthy or own a home or be married to adopt, and that there may actually be kids out there who wouldn't mind that I don't make $200k a year or that I need to budget for large purchases. Am I disqualified from adopting because I voluntarily shared guardianship of my biological child with my parents?