Include RTL Hebrew within English website

Our website is primarily English, but occasionally we want to include a phrase in Hebrew. We do NOT want to translate the entire site into Hebrew, just want to be able to display some Hebrew text mixed in with the English.

I installed the WP-RTL plug-in, which “Adds two buttons to the TinyMCE editor to enable writing text in Left to Right (LTR) and Right to Left (RTL) directions”.

But the FONT is still wrong. The characters all turn into question marks.

So I tried making the Heading 6 font in the Highend Options – Font Settings specifically for Hebrew. I added the Tinos font, which is a decent Hebrew display font. But eh Font Subsets list does not include Hebrew. How do I add Hebrew to the font subsets? Or do I need to do something else in order to add Hebrew?

(I also tried changing the H6 code in the CSS document to Tinos, but that did not work either).