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Well, that depends on a lot of things, especially what you mean by "too big." Some birds will naturally lay very large eggs; while this can put them at a higher risk of reproductive issues, there's not really anything that be done for it except enjoying those tasty jumbos! Also know that young layers (started within the past several months) wil lay weird eggs; big eggs, little eggs, shellless eggs, and so on. If she's not young, and is inconsistently laying large eggs, or is also laying deformed, shellless, or otherwise abnormal eggs, that could be an indicator of several potential issues.