Miranda Lambert is ''sad'' following her split from Blake Shelton.

The 31-year-old singer has been ''taking it day by day'' since 'The Voice' USA mentor, 39, quietly filed for divorce after four years of marriage in Oklahoma two weeks ago.

A source told PEOPLE.com: ''[She's] sad and trying to process everything. She's doing the best she can and taking it day by day.''

The duo, who got married in 2011 after six years of dating, released a joint statement on Monday (20.07.15), saying: ''This is not the future we envisioned. And it is with heavy hearts that we move forward separately. We are real people, with real lives, with real families, friends and colleagues. Therefore, we kindly ask for privacy and compassion concerning this very personal matter.''

The 'House That Built Me' hitmaker is still trying to come to terms with the decision, as their divorce was finalised just hours after they confirmed the news because they had a prenuptial agreement, which enabled them to swiftly divide up their assets.

The blonde beauty is said to be keeping their home in Nashville along with their rescue dogs Jessie and Waylon, while Shelton is holding on to their Oklahoma ranch and dog Delilah, according to UsMagazine.com.

They also plan to split their horses evenly.

Meanwhile, their mutual friend Chris Young, 30, insists he had nothing to do with their sudden split.

The country music singer wrote on Twitter: ''I don't normally address gossip but in this case I will. My name has been mentioned as a contributing factor in Blake and Miranda's divorce. That is totally false. They are both my friends and I would not betray that friendship. Just wanted to clear that up. Love you guys.''