Who am I writing for?

I'm about to start thinking about a new Molly Murphy mystery and also to come up proposals for the next three Lady Georgie books and I realize this is becoming harder than it was before. Not because I'm running out of ideas--far from it. I keep coming up with fun little twists and interesting plotlines for both series. The problem is that I am now so engaged in social media that I am in constant contact with several thousand fans. And they tell me what they like. I heard a lot of griping because Darcy did not figure prominently in Naughty in Nice. Of course there was the dashing and sexy Jean Paul de Ronchard instead but for keen fans of the series it just wasn't the same.

When I started writing mysteries I literally wrote for myself. I didn't think what might sell, what might make the NYT bestseller list or what might win an award. I knew what story I wanted to read and I couldn't find it on the shelf, so I wrote it. Now I feel all kinds of pressures--good reviews, bestseller lists, and above all pleasing my readers. It's got to be fun and sexy and dramatic and a good story but most readers want the story to be a personal one for Molly and Georgie. They want romance and heartbreak. They want their emotions involved.

This is now mmore of a challenge with the next Molly book because if you read Bless the Bride you'd know that Molly is now married. No more of that lovely romantic tension or the will they, won't they. So I have to think long and hard about where I want to go with that series. Children of her own to worry about, I'm sure. Daniel in danger. Cases that involve her personal life. So.... any suggestions as to what you'd want Molly to do next?
This raises an interesting point: should a writer keep her readership in mind when she writes, especially in a popular series. If the publishers had their way, we'd write the same book, over and over. Find a popular concept and stick with it. Look at Patricia Cornwell--that's exactly what she's done. Until now I've gone where I want to with my heroines, tried new things (like Molly meeting Houdini) and different tones for the books. But now I'm increasingly aware that my readers expect a certain kind of book when they see my name. Added pressure to perform and to please.
So, dear readers, what do you think? Should a writer write to please her readers? Should a series be consistent in tone and darkness so that the reader knows what to expect?  Do you get bored and lose interest if the stories are too similar or annoyed if they are too different? I guess I'm trying to please everyone and in the end the only person I can please is myself.