You don't always see the clumps as you are milking, but after the milk sits a while the clumps will circulate to the top and arrange themself into a bunch of clumping stuff. Pour some in a small jar and put a lid on it. Let is sit for several hours. Then check to see if lumps have risen. In really bad instances it can smell bad or the clumps will turn a greenish color. If it gets that far, you have a severe case. Right now I hope she has a mild case. Keep milking her out since constant draining of the udder is important to keep the infection at a lower level. If you can keep any mastitis to early signs, keep milking - even 3 times a day to keep the udder empty but DON'T stop milking to dry her up since that will affect the udder. Treat her with a mastitis infusion that you insert in the teats. She won't like it! Make sure it is an antibiotic infusion for does or cows IN MILK. Follow the instructions on the tubes.
Treating her will be more successful and she might not get it again if you keep her empty by milking. You will have to infuse after each milking. After she is cured, milk for a normal lactation and when you dry her up, use antibiotic mastitis tubes for dry goats NOT IN MILK. These are designed to medicate her udder while she is dry and keep any mastitis microorganisms from forming. That should keep her healthy for next kidding. Hopefully she will not get it during her next lactation with this practice. If she is housed with other does, watch them carefully and decide if you want to infuse them after you dry them off as a precaution. i once had a ewe freshen with mastitis on one side. She had never had a live birth before so I suspected she had leaked some milk after the dead baby was born that carried an infection into i her udder. It sat there until the following year when she kidded and flared up. She raised 2 large lambs on one side. After that I infused her every year when she was dry after weaning lambs to avoid a repeat. She never milked on that side again though. REMEMBER DON'T DRINK THE MILK OR FEED KIDS WITH IT UNTIL YOU ARE SURE THE MILK IS CLEAN. iT IS OKAY TO GIVE IT TO CHICKENS. iT WON'T BOTHER THEM.