I think Pegs likely asked Angel to deliver the body to the Mallers because he was the best and most trustworthy person available to do it. Saul was injured, Michael was with her, Burt would probably skull f**k Latch, Datu would have to drag it all the way, and Pegs was too chauvinistic to ask Riley or Lizzy.

But I've always thought the idea of a Pegs-Family connection to be intriguing. Angel told Kalani that he learned of John's name via Pegs, who in turn learned it from Scratch's screaming after he was shot. (Her name should be Scream, not Scratch) But Peg's nightmare made me wonder if it was simply guilty conscience or if she knew something of Family dynamics. Latch speaks to her in her dreams as if she knows something that we don't obviously see.

As for picking out Marcus' name within a Spanish conversation, well, she's in California with quite a bit of Spanish speakers. I actually picked it out on the first listen. I live around a lot of Tagalog speakers and often recognize names, places and objects mixed in the Filipino vocabulary.

After re-listening the the 'Marcus is in charge' part, it seems she is just establishing for the audience that the person mention in the radio message in the head honcho. Tanya just mentions Marcus' name without any introduction. His name is just too common for Pegs to know who he is.