Like Michelle said, it takes patience and practice Zee. Good for you for starting testing!! It's going to help so much for you to know if it's safe to inject and see how the insulin is affecting her.
I suggest de-sensitizing by taking Mum to the testing station, offering the treat, rubbing and handling her ears, let her see the testing equipment and let her sniff it. You can use a rice sock (small cotton sock with about 1/4 cup uncooked rice or oatmeal, tied off and warmed in the microwave for 15 - 20 seconds) or an old pill bottle with warm water to bring the blood to the surface. Give her another low carb treat and let her go. Do this as often as you can throughout the day. We use a thin smear of pain relief ointment on the ear, it helps the blood bead up and then I rub just a smidge again after I have compressed the "poke" site with a cotton ball for a few seconds to help prevent bruising.
There are very few pain receptors in cat's ears, they mostly object to the handling until they get used to the testing process. If you were using the lancet device, the click might have startled her, more than feeling the prick of the lancet itself.
Have you been able to review the home testing links and tips?
http://www.felinediabetes.com/FDMB/threads/hometesting-links-and-tips.287/
Now that you are home testing will you set up the spreadsheet so you can enter the insulin and testing data
You will see how the trends and patterns emerge, and members can review her progress before offering suggestions or advice:
http://www.felinediabetes.com/FDMB/threads/fdmb-spreadsheet-instructions.130337/
http://www.felinediabetes.com/FDMB/threads/understanding-the-spreadsheet-grid.156606/
If you have any problems with set up, let us know, there are members who can help.