Michaelbe,
My former supervisor's email box use to be flooded with emails. He old me a 'secret' to emails. Read the at the end of the day and respond then.
Ringing phone at work ... voicemail.
If you have an office, close the door. Scatter some papers all over the place to make it look like you are deep into work.
At home, my favorite trick is to go into the washroom, close the door, pretend your doing you know what and PR ... trick is to do it in about a 20 minute session. Any longer, and the wife might catch on!
As for your little girl ... the fact she wants you to read to her is a fantastic thing. You would be doing her a great service. It's a great way to bond. It helps you to remember to enjoy life. Kids are only kids for so long. Now here's the trick, every so often, have her pick a book from daddy's pile!
I know the feeling of tired. I too have youngin's and another is in the oven!
One suggestion is to get up an hour early in the morning than you usually do. Here's why. When you wake up, it a new day, it's a new you, its a new start, it's a fresh start, it's a clean slate, a new beginning. It's like being born again ... learning/reading in the morning is refreshing as the body/mind have had time to recouperate.