How do I tell my mom, who is greatly opinionated, that giving her advice repeatedly is not always welcome? I don't want to hurting her feelings.

You don't give us much information to go on here, other than you apparently all live together which is your first mistake.
I'm sure you were well aware of how your mom was long before you decided to live with her, and because you can't ever change someone else, I guess your husband and daughter will have to change themselves in this situation, by either keeping their distance, or just putting her in her place when she gives her opinion.
Or better yet, if you're living with her, move out and get your own place so you can have peace in your home.
And if she's living with you, time to be looking into an independent or assisted living facility for her where she will be around other folks her own age.
The fact that you don't want to speak up to your mom and defend your daughter and husband who are being bothered by her opinions, because you might "hurt her feelings" says a lot about you now doesn't it?
It should be your husband and daughters feelings that should be coming WAY before your moms feelings, just FYI.

How old is your Mom? Does she have dementia? If so, the only people who can change their behaviors are your husband and daughter. The ball is now in their court moving forward.

They need to redirect or distract the conversation. They need to understand it is now pointless (and exhausting) to try to reason with someone who is rapidly losing their reasoning and logic skills, and their empathy for others. Her filter is falling apart and can never get fixed.

I learned a lot from Teepa Snow videos on YouTube. She gives lots of great tips on how to interact with our LOs with dementia for more productive and peaceful engagement.

Hubby and daughter need to politely tell mom that when they want/need her opinion they will ask but until then she needs to keep it to herself.

Does mom have Dementia? If so, she won't stop her opinionated, free-advice giving behavior, period. Inviting an elder to live with you also invites all their idiosyncrasies and annoying behavior into what should be your sacred space.

If not, tell mother you've heard her advice repeatedly but prefer to make your own adult decisions in your own home. If she can't respect that, she can move into senior housing. Your home, your rules and your boundaries, for your husband and daughters sake. You may be light hearted, but she's bugging them in their own home!

I suggest you, your husband, and your daughter speak plainly but not unkindly to her and say what you mean.

Tell her in simple terms that none of you want her opinion and imput on everything. Also, that if any of you want or need her advice on something no one will hesitate to ask for it.

Be upfront and honest. This is not unkind behavior. If she acts affronted when you tell her this, ignore her. That's just attempting to make some drama.