Should I cancel this birthday cake?

I (28F) recently ended a toxic friendship and I'm conflicted about a birthday cake I ordered for her 3-year-old daughter's party next week.

We lived in the same building. I helped shovel her car during a storm when she had a newborn and invited her to events, but she ignored me for 2 years until she saw my car and body and wanted to hang out.

Over the past year, I:

• Planned her daughter's entire birthday party, got decorations and ordered the cake
• Paid her 30th birthday dinner bill after warning her I was uncomfortable (didn't know her friends' contact info). She left me holding the bill anyway
• Supported her through her husband going to prison and during the domestic violence (it was horrible)
• Offered business advice and free lawyer contract review (both rejected)
• Gave her my clothes

She constantly copied everything - furniture, clothes, recipes, even bought my exact bed 2 months after I did.

I'm Ivy League educated with a successful career. Her business is failing - she took maximum loans on a stranger's advice, opened an out-of-state phone store, now works there Friday-Monday sleeping at the location with no bed/shower and is facing bankruptcy at 30.

Her husband (in prison) stole $20K from her, never paid bills, gave her two black eyes. She watched me have the opposite - a fiancé who paid bills and treated me well. Ironically, relationship problems started exactly 4 weeks after meeting her.

She:

• Showed up in PAJAMAS to my Thanksgiving (after dressing nicely for 2 others)
• Made jealous comments about my body/money/possessions
• Pressured me to commit insurance fraud for weight loss meds for her
• Stalked my ex-fiancé, timing arrivals to "run into him" (I witnessed it for weeks)
• Called him after our breakup to "help me get over him"
• Said she wanted someone "like him" who provides financially
• Tried provoking fights between us, saying "I'd slap him if I were you" when I'd never put hands on my partner

She pressured me to buy her daughter a tablet (I don't believe 3-year-olds need them). When setting up, I declined using my number. She asked my ex-fiancé to use his instead.

Days later, he felt uncomfortable his number was linked (you can bill Google Play to phone accounts, plus her abusive ex might see it) and asked me to address it. I asked her to check the settings.

She got DEFENSIVE, called, screen-shared (wrong settings), then when I calmly said her response seemed anxious and showed her the correct settings, she threatened: "Don't take it there because if you want to go low I can go very low."

I blocked her immediately.

Before this, I ordered a custom cake (she expected 30 cake pops too). She may not pick it up, leaving me to pay.

My ex-fiancé and cousin said cancel. I'm struggling with guilt about the child not having a cake, though rationally I know mom will figure it out.

What should I do?

Thank you!