My mother wants me to change my date

So my mother keeps pushing me to change my date. A conflict has come up with my FMIL inviting people from their work (they work at the same place) including one person who was fired and my mother has a lot of issues with this. Plus, my mother has concerns about FH's maturity levels- which she complains about. Now, my mom has told me, since the guest list has grown she is worried about how much the meal will cost since she has committed to paying for the reception dinner. FMIL has said she will pick up the tab for her extra people, but my mom is super upset. Which has lead her to ask me to push my wedding off by a year. She says she will have more money later and hopes some of these guest list issues will calm down. I know FH wants to get married this year and I do too. I am so stressed!