Recurring Miscarriage

I have just had my third miscarriage in 2020 on Dec 29th. I was going in for my 8 week ultrasound, and started bleeding when I went to do a urine sample right before the ultrasound. I have an year old at home and for a year she has been telling me she wants a sister. She plays with an imaginary friend she calls sister. I feel like I'm not only hurting myself and my husband by continuing to try and miscarrying, but I'm also letting her down by not being able to give her a sibling. My husband and I have been trying for over 2 years now to get pregnant again and my daughter likes Frozen so she wants a sister like Anna and Elsa.