Is this a lethal combination and the reason i am asking is my friend is depressed and told me she has some zzzquil, sominex, lunesta (eszopiclone) ?

PROBABLY NOT: Most over the counter sleep meds are just benadryl. Lunesta (eszopiclone) is prescription. If that much sleep trouble needs to discuss with a physician.

Intervene?: If you are a real friend, then please consider going to her place, taking these medications away (a big dose of an acetaminophen-containing medicine might be the most deadly) and taking her to see a suicide help person now. Sometimes this is the way to escape being trapped in a terrible situation or with the wrong mental patterns. It's up to you.