Disaster baby shower!

Baby shower is in 2 weeks. Mom knew the date and time since May...decided last Monday she would send the invites so ppl only got them last Thursday...n the venue needs a total head count by this weekend. Most ppl already have vacation plans. So my guest list went from 100 ppl to 10, n that's including my husband and our parents. So really that's only 4 guests... N my mom somehow doesn't see that this is her fault. N what makes this entire thing worse is my step mom offered to help several times but my mom insisted on doing everything herself that she "didn't need help". I'm freaking out I'm so pissed. No excuse for taking 2 months to send out invites. If ur busy n u have ppl offering help take the freaking help! Sorry I needed to vent