Kylie should be 4 months and 3 weeks today, if the shelter gave us the correct age. The vet said that they were within 2 weeks of the correct age for sure (because she was supposed to be 10.5 weeks when we got her and she had all of her puppy teeth and because her front teeth were all adult at 4 months, right when they should have been).
Exactly one week ago, she was 31 pounds. We haven't weighed her yet today. We usually weigh her using the Wii Fit Plus every week. It has always been within 10% of the weight we've gotten from the vet, so it's reasonably accurate. She's been gaining 1.5-2 pounds each week.
I just had her stand next to the yardstick. Her back is at about 20 inches and her head is at about 24-28 inches.
I'm going to guesstimate that she is probably 32.5-33 pounds now, but I won't really know until I weigh her later. My 14yo is playing Twilight Princess on the Wii right now, so I can't check her weight until she's done.