1) You can't force her to pay you unless she agreed to share the costs with you--if you and your sisters agreed to split the costs and pay for the funeral but your stepmother never did, you can't legally force your stepmother, who hadn't agreed to pay, to pay.2) There is nothing illegal about her keeping the extra payment for your father's death.3) There is nothing illegal about her getting engaged shortly after his death.Based on what you write, your stepmother may be acting immorally or unfairly, but not illegally.