Husband trusts his sister to care for our children more than he trusts me.

I'm a mother of two 7yo twin boys with and I'm very distressed that my sister in law is more respected and influential on raising my children than I am.My sister in law is 8 years younger than me, has never had kids but is a psychology specialist and has several degrees and qualifications in child psychology and development. I don't have any fancy degrees and I'll admit I don't always have the right answers and make a lot of mistakes in raising two boys with developmental issues, BUT I am THE MOTHER. So I should be the authority right? Apparently not.From the time they were infants my husband, and everyone else in the family has deferred to his younger sister more for directing and handling how the boys are taken care of and what the best parenting choices are and it's infuriating to me.I had post pardom depression after giving birth and for a time our extended family really had to help me and my husband because I was such a mess. During this time everyone in the family made a huge fuss over how "amazing" my sister in law was with the babies. Because it just so happened that she was the only one who could them to stop crying, get them to bottle feed, and get them to sleep. The family called her "the baby whisperer" and always asked her what to do for the boys, even flat out IGNORING my input as a mother sometimes! Even then I'll admit I was very jealous and upset that she was able to care for them more than I was, and my envy was a big motivation in working towards recovering from the PPD.After I recovered she remained the primary female influence on raising the boys. My sons both have developmental disorders that she's "highly educated" on and she's always got the right answers and the right tactics to magically come out as the one who seems to be and appears superior in caring for them. Especially after several instances where I asserted my parenting plans and approaches to handling their developmental issues and these plans happened to technically "fail". Then after those failures of mine her suggestions went (admittedly) perfectly. My husband now completely stopped taking my word over hers for anything to do with the boys.It's gotten to the point where my husband gets annoyed/angry with me and the whole family acts like I'm being stupid if I go against what she says is best for the boys. Just because there have been times when what I wanted to do had bad results and hers had good ones.I've tried expressing these feelings to my husband but he just gets exasperated and tells me I'm being petty for not appreciating how "lucky" we are to have someone like his sister. I AM appreciative that she's in our lives. Without her help I honestly don't know how we would have even handled quite a few very hard situations and if I'm being honest I have to admit even to myself that when it comes to their developmental issues she knows a lot more than I do. BUT I'm just so tired of feeling as though I've been dethroned as the mother and of the entire family acting as though she is so much more important to the boys wellbeing than I am. What can I do?! Any advice or insight would be very loved and appreciated.TLDR: Entire family respects sister in law more than me as the person who knows what's best for my boys because she's got a better track record and I've made some mistakes. I've basically been dethroned as the mother. Talked to husband about it and he thinks I'm petty and should just be happy we have his sister to help us. I know I DO want/need her help and that she's better at a lot of parenting things than I am, but I still want to be the one who's respected more and has a higher standing as a mother.Cross posted to /r/advice and /r/RelationshipAdvice via /r/Parenting http://ift.tt/2bCJRR5