My nine-month old English Boodle is very sweet and playful. She's never shown signs of aggression towards me or my family, or any other dogs - sometimes she tries to play with the cat, but usually gets smacked in the nose. I have noticed that when I go to pick her up, sometimes she growls at me. I immediately let go of her and back up. I'm not really sure what to do, she's not a mean dog and has never bitten anyone. She still acts like a puppy and is very friendly, but I'm still worried.
Most people only know a growl as a sign of aggression, but it can also be a verbal expression of displeasure, pain or apprehension.
First you should check your own body language. Are your legs straight and your torso bend down at the waist? Then you are towering over your dog which is a very aggressive gesture in dog body language. Her growl is just her answer to your aggression.
You should always bend your knees and keep your torso mostly upright to get down to her eye level. This way you avoid sending aggressive signals.
If that doesn't change the situation, picking her up might cause her pain. That could be either you pinching her or her back, ribs or joints hurting. You should support her weight with one hand between her front legs, holding her rib cage, and the other hand offering a platform for her hind legs to stand/sit on.
If you cannot find the cause of her pain, it's a good idea to get her checked by a vet.