How do you express a thesis based on the similarities of "Two Kinds" by Amy Tan and "Everyday use" by Alice Walker?
It needs to be arguable, and not refer to actual character, but generalize about the significance of the central events of the story.
For example, both stories explore the cultural conflict between mothers and daughters.
To be honest, I think that the suggestion you have given above is actually a good start. Clearly, what you want to focus on is the similarity of theme between the two. Both of these brilliant stories focus on a relationship between a mother and a daughter (or daughters) and the way that culture impacts that relationship. In the case of "Two Kinds," it is the mother's insistence that Jing-Mei be brought up to achieve great things that comes into conflict with Jing-Mei's own desire to be mediocre and to live her life her own way. In "Everyday Use," it is the conflict between Dee and the way that the discovery of her African heritage has changed her and her mother that is the focus of the story. The intertwining of cultural differences with inter-generational conflict can therefore be the basis of your thesis statement. What about this statement as an example?
Both "Two Kinds" and "Everyday Use" explore the theme of intergenerational conflict by depicting how differences in culture lead to an external conflict between daughters and mothers.
This would allow you to focus on the key similarity of conflict in these two stories and how it is expressed, and also it gives you the chance to talk about the different viewpoints expressed and how culture impacts those viewpoints. Hope this helps and good luck!