You should be fine- this isn't that uncommon as it's really easy to leave a little piece of shell on a hard boiled egg. Remember, even if she didn't wash them- the whole egg has been boiled in high temps which would kill off any germs.
When I was a kid, people never even put the colored Easter eggs in the frig and we would eat them for a week! I think about that now and I think YUCK. lol Truth? I've never washed eggs before boiling or cooking or using. And boiling sterilizes things (think baby bottles.). :) No worries hon