She adores the friend, but it is a reminder that she is not the most tidy of housekeepers, and the idea of people dropping in on her makes her shudder.
In reality, her house is not filthy, just lived-in. Sure, there are piles of mail and projects on the table, but there are always seats open on the couches and the coffee maker is easy enough to find. What else do you need for a visit?
It is so easy for us to see where others are doing better than we are, and for that to race into our deepest anxieties and shame. There's no checkpoint on that route where we stop to consider our own strong points or how our realities might be different from someone who seems to be exceeding our abilities. Because those would be rational things to consider, and neither anxiety nor shame is especially rational.