@Boz -

Let's compare what Helen actually heard say, with your paraphrasing, and see if we can identify the problem.

Helen:
“It’s amazing/surprising/something-allegedly-positive-but-expressing-a-contradiction-to-perception to see a female developer.”

Boz:
...not bad for being a girl...

The way I see it, the problem is in the difference between implication and inference.

What Helen quoted could easily be interpreted as the speaking expressing delight at seeing someone excel according to her own abilities, despite prevailing circumstances and prejudices. Such an interpretation implies no condescension whatsoever, and is both complimentary and encouraging.

I say this not to counter the points Helen made in her blog post, but rather to challenge your gross paraphrase of what Helen quoted. If you read that quote, and all you hear is, "not bad for a girl", then the problem lies in your own inference.