Complex sentence: Margaery instead pleads for Olenna to return to Highgarden instead, slipping her a piece of paper with the sigil of House Tyrell drawn on it, indicating that she is still loyal to her family.
Split into simpler sentences: Margaery instead pleads for Olenna to return to Highgarden instead. Margaery then slips Olenna a piece of paper with the sigil of House Tyrell drawn on it, indicating that she is still loyal to her family.