Facebook, Twitter and Linkedin content management

Hello!
We've recently launched our business and have already got an engaged and growing instagram community where we're already struggling to find time to continue growing but have no time to build our facebook and twitter followings. We're looking for some support to grow these platforms with content that's relevant for our audience (ethical pet owners, millennials) and helps us stand out from the crowd with a humorous, relevant tone of voice.
Let me know if you can help
Aneisha