Erin Foster defended her stepmom Katharine McPhee from online trolls.

Her dad David Foster shared a picture of the singer showing off her post-baby bikini body on his account.

The share received plenty of negative feedback.

Today, McPhee blasted her “haters” on Instagram and shared another swimwear snap.

McPhee wrote in the caption: “I’m sorry but we are not sorry. And for all of you who can’t deal with it maybe this helps. I’ve struggled with weight my whole 20s and 30.”

She added: “BUT people freaking out about what my husband captioned seriously get a life... Stop being so offended by what people post who have zero impact on your life and move on.”

Foster commented on the share by writing: “If I can accept my step mom looking like this, you certainly should be able to. The photo wasn’t altered or filtered and she’s had no surgery.”

She continued, “You can’t shame someone for feeling cute after a baby whether she’s sharing stretch marks or a six pack. Let her live.”

McPhee appreciated Foster’s support and wrote back: “I love you 😂 always funny AND supportive. Don’t tell them about the lypo tho.”