Absolutely! I would suggest talking about motherhood in regards to this Modernist work. How about this:
Pregnancy and motherhood become symbolic of tradition and normalcy in Quicksand.
Of course, you would begin with an introduction about modernism and the changing of women's role in the 20s, but whittle it down to that thesis. In regards to the body paragraphs, it would be so easy to use Helga's experience in the book to prove your point.
Perhaps the first body paragraph could be about Helga's mother choosing traditional marriage (yes, to a white man) so that Helga could grow up seeing domesticity as the mother's role. Helga, of course, reacts against this always being "in search for something." I would say in search of something ELSE. She begins her escape as an escape from that tradition. (However, it ends up tethering her just the same.)
Another body paragraph could be Helga's reaction when she finally is a mother. Her sense of longing for that "something" becomes real. Instead of something positive, motherhood becomes something negative. Helga, then, is reacting AGAINST the traditional norms. You can hear it here, where Helga speaks about birth.
It wasn’t a miracle, a wonder. It was, for Negroes, at least, only a great disappointment. Something to be got through with as best one could.
Finally, another body paragraph could be the tradition feeling like Helga's "trap." This trap becomes real for Helga. She couldn't escape the traditional female role. Now she is trapped, tethered, and confined. Helga cannot escape. Motherhood is forever. So is tradition.
In conclusion, you could restate your thesis, and then talk about how interesting it is that tradition is held in a negative light for someone like Helga. It is the opposite from the usual positive connotation of tradition.