Investors & landlords

Based on what I have learned here the amount that will be considered gift is approximately $150,000.  That amount was jointly given by my wife and myself to our son and daughter-in-law jointly.  Therefore, if I see it right, $64,000 of that should be exempt.  The balance will be applied to our lifetime exemption.   I'm now wondering if my wife and I need to file separate 709's showing our gift shares separately, or can we jointly use the same 709?  Thank you so much for all the great assistance.