Do not build straw men. I haven't said EJ is not a reliable source. As for Wikipedia, it is a tertiary source according to own's Wiki policy article (this page was recently merged): "Tertiary sources are publications, such as encyclopedias, that sum up other secondary sources, and sometimes primary sources. Wikipedia is a tertiary source. ".
 The claim can be see as exceptional as it a) conflicts with many published biographies (were is stated Romanian father, French mother) b) conflicts with the image propagated by hiw own family (his daughter) c) even so, it is admittely a controversial issue. Even among the scholars admitting Eugene Ionesco's Jewish origin, we find scholars like Alexandra Lagniel-Lavastine saying Ionesco's Jewish origins are "certain but remote" (the quote is from memory). 
 [WP:BLP] applies for one main reason: you're discreding her testimony. I'm not removing sources saying otherwise, I'm just objecting to the way they are balanced. Go for mediation if you believe it's necessary, but I hope we can solve this with common sense and arguments.