One place I especially like to work on is charged relationships. Partly because this is an area where I have had my own work to do, so I know how important it is, but also because we really discover our own thought processes here and they are funny and surprising.
Several of you wrote in asking me to discuss sibling relationships. When I put out a request for specific scenarios, they were almost all about sisters-in-law, so we'll focus on that but these tools really can be applied to any relationship.
I have a question about my sister-in-law. I desperately want to become friends with her but every time we do something she is constantly on her phone or gossiping about people from her home town that I have no clue who they are. How can I become friends with someone who doesn’t take the time to talk?
There are two parts of to any relationship: how they feel about you and how you feel about them.  Which is in your control? We will never know how someone feels about us, and even if we could know, we can’t control it.
So I like to have a few thoughts that help me:

I get to feel however I want about you.
I am going to learn something very important from you. 
I’m good. 

How do I deal with a jealous sister in law who wants to make every moment about her? She wanted to know when I was pregnant, when I gave birth, and gender of baby (I’m assuming she means during the pregnancy) and got jealous of my relationship with my MIL. I don’t have involved parents.
Let’s break down what’s happening and how we’re interpreting it. Because our interpretations drive our emotional reaction, so we have to have really high standards about what we’ll allow as “fact.”
What happened: she asked if you were pregnant (or asked you to tell her when you were)
Thought: She needs every moment to be about her.
Feeling: Resentment, annoyance, disgust, sadness… whatever
Action: Don’t tell her, maybe try to convey with your tone or body language that you’re offended
Result: Less closeness, no pairing of you two, so it remains all about her--there isn’t a relationship instead. 
What if you tried on other thoughts here? How would you feel and behave differently? Have some fun with it.
I had my son 9 months ago and my SIL got married 6 weeks before us. Lots of tension. I had a great pregnancy and she is now pregnant and I am extremely happy for them. But at the same time I all of a sudden feel a shift in my MIL since hearing the news. I understand it is her daughter and she is pregnant with her second grandchild, but she is seemingly colder towards me… it may be my own insecurities but what if somehow it could be my SIL stirring it up? She is very insecure with my husband and MIL’s relationship.
How do you want to show up in the relationship? Create a clear vision for yourself before any family interaction with your in-laws. It is very normal to feel uncomfortable with your in-law relationship. What if you allowed that? What if you didn't try to make it more comfortable, but just went to a place of observing yourself and your reactions and allowing yourself to be uncomfortable?

Want to take this work further? Watch the free video at www.firstyearmarried.com to learn how to coach yourself.