This is a brilliant question based on some very astute observations. Of course, as with any question, it is important to consider the arguments against such a position. Joseph Storm for example is a rather indomitable male, and certainly keeps his wife and his household firmly under his thumb. However, the statement appears to be particularly true when we compare David to the various women he comes across. For example, again and again Rosalind shows herself to be quicker thinking and more ingenious than David. It is she who kills a man who is pursuing them, and it is she who carefully packs and prepares for their journey to the Fringes:
I realised that Rosalind had put in some careful planning to hide our tracks. I must have projected the thought unwittingly, for she came in, somewhat coldy:
"It's a pity you didn't do a little more thinking and a little less sleeping."
In fact, if we examine the character of David, he shows himself to be something of a weak and ineffectual male. Rosalind seems to be the brains behind this union. Likewise, in the Fringes, he is dependent on Sophie to release Rosalind and Petra. Lastly, you might want to consider the character who is presented as being most dominant of all: the woman from Sealand. These are excellent examples you can use to explore the strength of women in this novel.