Hi, I'm looking for some advice for my 13 week old dd3.
Dd3 was born weighing 7lb and she is ebf. She regained her birth weight at 2 weeks. I didn't bother with baby clinic and she wasn't weighed again until she was 9 weeks and had her check up and jabs. She was 9.4lbs and the hv was not happy, told me to come to baby clinic. So I go back 2 weeks later she is still 9.4lb.
So I've spent the last 2 weeks offering her the breast in between usual feeds and loads of skin to skin. I did try expressing with a hand pump but didn't get much milk, she does a much better job. Went back to the clinic today and she is 9.9lb, which is apparently still not enough. She was born on the 50th centile and is now below the 2nd.
The hv suggested introducing formula or considering early weaning. I told her I was not happy with either of those suggestions and asked if she had any alternatives. She said no and she was going to refer dd3 to a doctor due to her poor weight gain and I quote "as you are obviously too stubborn to take my advice onboard" 
Dd3 is a happy, contented, smily baby. She feeds frequently throughout the day and sleeps for 6/7 hours at night. She has recently started to take a dummy when she is tired. She has plenty of wet and dirty nappies and has started to outgrow her 0-3 month clothes so she is obviously growing.
I'm small (5 foot 2, 7.2 stone), my other children are small but within normal range.
Am I doing anything wrong? Should I be worried? Is there anything I can do to make her put on more weight?
TIA.