Final answer:
Helena plans to inform Demetrius about Hermia and Lysander's elopement, hoping to gain his affection.
Step-by-step explanation:
The question seems to be slightly mixed up because Helena is a character from William Shakespeare's play A Midsummer Night's Dream, not from the excerpts provided which appear to be from Henrik Ibsen's A Doll's House and a possible Shakespearean-inspired work with characters like Polonius and Horatio, from Shakespeare's Hamlet.
However, to answer the intended question, after hearing about Hermia and Lysander's plan to elope, Helena decides to inform Demetrius, whom she loves, in hopes that he will love her in return for her loyalty.