How long should a bike last before the wheels wobble? I bought a bike for my girlfriend about six months ago. It's a women's road bike.

She's rode it a bit, but all of it on the road. She's never crashed it and it's always been in good care.

She's taken the wheel off a few times to put into a car. But yeah, each time we've taken good care of it.

Today, I noticed that the wheels were touching the brakes. It's been doing more and more later, so I've had to re-adjust and widen the brakes, but today, I realized that unless I completely undo the brakes, it won't touch.

I turned the bike upside down and realized that it was touching, because as the wheel is spinning it was kind of wobbling. 

Now I'm not sure what has caused this. Like I've said, we've had it for six months, but it wasn't like we rode it all the time, the bike has never crashed and as far as we know, we've always taken good care of it.

So is it like a fairly normal thing? Is it possible to get it fixed? Could it be a flaw with the product? Should I be ringing up the bike shop I bought it from to complain? Or is six months like too long, and I should be expecting things like that to happen?

I have a Fuji Absolute 4.0 - it's been a fairly good introduction for her into riding I think. Nice and light.
It is normal for a wheel to have an initial break in period.

As you ride the bike, each spoke has its load released, and retensioned each time it passes around the bottom of the wheel. Since some parts of the wheel are aluminum, and others are steel, the aluminum parts compress. This means that the spokes are not under as much tension as they need to be. 

Since not every spoke will compress exactly the same amount, it makes some spokes looser than others. 

A wheel's strength comes from having the spokes act like the wires of a suspension bridge. As long as they are under the correct amount of tension, and the tension is equal on each spoke, the wheel will stay straight and strong.

A single loose spoke will allow a wheel to detension, and come out of true. If you ride the wheel in the detensioned state for any length of time, you can damage the rim, and make it impossible to make the wheel perfectly straight, round, and strong again.

This process of break in takes different periods of time for different wheels and different riders, but most bike shops recommend a service on the bike within 30 days of riding it the first time. That should include a wheel service.

Six months is too long to expect them to fix it free, although they might do it to build good will with a customer of theirs. I would not go in and complain, but do go in and ask them to explain why it happened. Make sure you speak to a professional mechanic or manager, and not the high school apprentice mechanic.

Be friendly about it, and a good shop will likely fix it, if possible, without charging you. At the very least, you will get an idea of what kind of shop they are, and a real idea of it is repairable or needs to be replaced.

I hope that helps.