Final answer:
Angelika initially goes to Peter's house for practical reasons; she answers the door because she is alone in the house. Her ongoing visits have various inferred reasons, including emotional connections and professional matters.
Step-by-step explanation:
Angelika goes to Peter's house for the first time in the provided text due to pragmatic circumstances; she is the only one present and decides to answer the door, reminding her of the previous engagements she had during the 'old days' with Madame.
There is no explicit statement that defines her initial motivation to visit Peter's house, but as inferred, several scenarios suggest different reasons for her visits.
For example, she could be returning out of necessity, driven by her evolving emotional connection to Peter, or possibly due to professional reasons related to her work with fabrics and designs.