Why does my daughter have better reception?

Hello. I've been an AT&T user for around 17 years now. I'm on the grandfathered unlimited plan. I have a question. I just got my daughter a phone through boost mobile and she has better reception than I do. I never have more that 1 dot of reception in my house and most places and she has 4 dots. I don't think I've ever seen 4 dots on my phone. How is that possible? Shouldn't I have better reception than her? Thanks.