She has read the message. She has not replied. You're now examining a period she used last Thursday as though it can tell you where the friendship is headed.
Psalm 56 names fear in the presence of real enemies. David turns toward God, whose care includes an intimate image of remembered tears. Trust begins with fear honestly acknowledged.
A delayed reply can't tell you everything another person feels. Neither can a facial expression or short email. Gather facts when needed; resist inventing a verdict about your worth. Bring fear to God before assigning meaning to silence. You can make a wise relational decision without refreshing your way into certainty. The read receipt has a remarkably limited job description.
A question to sit with
What reaction am I monitoring as though it could settle my worth?
You can take this slowly.