I think that would be too noticeable for Lois.
How about a date? Like her parent's anniversary or something. It would just come up in a conversation. Lois knew her real parents anniversary for certain, so that might set off alarm bells. Then, if there was other clues available, like different houses when she was young, she could start to realize something was wrong.
I think, therefore, I get bananas.
When in doubt, think about time travel conundrums. You'll confuse yourself so you can forget what you were in doubt about.
What's the difference between ignorance, apathy, and ambivalence?
I don't know and I don't care one way or the other.
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