Patrick & I love to exercise and we do - and you should too. Here Patrick, lift this. That's ridiculous isn't it? - He's four lbs and this is 15 lbs, he can't do it. Well the same thing is true for women. Women are different then men, and therefore the exercises are different. Let me show you what the differences are.
The first thing you need to do if you're a woman is to make sure that the weights are appropriate. A 15 lb weight is not appropriate for most women, but the 5 lb weight is, so make sure you don't go over your limit because you can hurt yourself. The other thing is be consistent - if you can't make that one hour workout go for 1/2 hr, go for 20 minutes, because even that amount of time will help you, so stay consistent
The next: it's important that you also vary the exercise. Just don't, for example, work on your biceps, work on your triceps, etc. If you don't know how to do it - get a trainer. My recommendation is that if you're serious about it and you should, get a trainer to begin with because then you know how to do it correctly and you won't hurt yourself and you'll get the most out of it.
The other thing is to add little isometrics into it. When you contract it - do it over 1 or 2 seconds, hold it, and then release it over a 3-4 second period of time. That's called isometrics and will increase strength of the muscle.
Next, you need to be especially aware of what's caled female-focused exercises, principally the back and the shoulder to maintain your posture, and also the hamstrings to protect your knees. Those are very, very important for women
Now if you do all those things and also remember it takes about 4-6 weeks to notice any effect, be patient, you're going to look good - just like Patrick and me here, you're going to feel good and you're going to get the most out of what you're doing and you won't hurt yourself.