Family arguments

..Family arguments SUCK! SUCK! SUCK!

I'm not going to get into much detail for respect of my family but I just need to vent about this and hopefully my sister's are reading this and know that I am not on ANYONE'S side, honestly.

Earlier today, my mom sent me a text of her hand with a big diamond ring on it..at first I thought maybe it was a joke and wondered why she didn't call me to tell me the news, so I call her and come to find out, she is indeed engaged! I'm happy for her! But let me explain why I am a little hesitant with this situation..

My mom, Tianne has been with Mike(her now fiance) for almost 3 years. He is a good guy, owns his own cooling/heating business and has two boys, whom honestly are the most well behaved & disciplined kids I've EVER met! Also, he's from Utah and comes from a very religious background as a Mormon. So he has good morals and values. My younger sisters Lindsay(20) and Tessa(13) along with the entire family really approves of him and is happy to see my mom so happy and in love, until just recently.
They bought a house together this past June but then things started to get a little rocky..they were constantly having this petty little arguments over the sillest things, I am not kidding..it was just sooo childish! It got so annoying and unhealthy for my mom and sisters to continue living there, so they moved out in November...well my mom and Tessa. Lindsay resides 40 mins. away at college.
To sum it up..he's been chasing her, begging for her to come back, and then it leads up to today...HE PORPOSED! My sister's are FURIOUS and neither will talk to my mom, they think she chose him over them. I understand both sides, I really do. I see why my sister's are so mad..they're sick of seeing/hearing them argue all the time. And I know why my mom is giving him another chance...LOVE. My sister's are too young to understand the meaning of love and what it's like to have a special someone in your life. Nobody can wake up one more and stop loving and forgetting a person, it takes a lot of strength.
Now my older sister, Lindsay won't talk to me because she thinks I'm teaming up with my mom..I told my sister.."I know you don't accept this and it hurts you but please be happy for mom." She didn't say anything back, and has avoided me ever since, well it's been 2 hours. psshh.
And I'm the one stuck in the cross fire..in my family I am the ONE that everyone goes to for being the first to know family secrets and all the 411..I mean, it's a good feeling knowing that my family appreciates my trust and support but it's hard keeping secrets..which can lead me on a whole nother topic but I won't get into that one on here!
I just hope we can get this straightened out..now my mom wants to give the ring back to Mike because Tessa and Lindsay won't talk to her..I feel bad for the guy, seriously..I hope it doesn't lead to that! I just wish Mike and the girls could talk and develop the relationship they had together..he is a good guy for the family and more so for my mom, she needs him, emotionally.