Mum expect us to drop everything so she can see GC

“She’s asleep mum, let’s have a brew while we wait for her to wake up”

“Fast asleep, loose woman are on the telly tho, do you want a sandwich”

She’ll either figure it out and change the time or just enjoy your company instead. And if she doesn’t like it, or starts making noises about waking GD up, it’s time to set firm boundaries and risk falling out.

If she doesn't live in the same house as you you don't have to deal with the the big to-do. She says she's coming over at X, you say baby will be asleep so come over at Y if you want to see them, I won't be opening the door at X so that they aren't disturbed' mute your notifications from her and let her mither on, don't answer until later on in the evening and say she made her choice, if she wants to see baby the following day Y (or Z, whenever) is a good time.
Essentially you are dealing with a child having a tantrum - this is good parenting practice for when baby is a toddler! She has learned that stomping her foot and whinging sends you into a flap and you ll give her whatever she wants to make her quiet. It will be a learning curve for her to realise that you really have boundaries now, but she's an adult, time to act like one. (and if you have to take the batteries out of your doorbell while she's learning so be it)

I travel 2:5 hrs each way to see my GC. I adhere to what parents say regarding nap times, sometimes having to cut short my visit but that’s what I expect. I wouldn’t dream of being stroppy. I agree that you need to be firm but I wouldn’t advocate lying ( saying you are out etc) as this could turn round and bite you on the bum.

I travel 2:5 hrs each way to see my GC. I adhere to what parents say regarding nap times, sometimes having to cut short my visit but that’s what I expect. I wouldn’t dream of being stroppy. I agree that you need to be firm but I wouldn’t advocate lying ( saying you are out etc) as this could turn round and bite you on the bum.

Your mum sounds quite manipulative. She can't dictate to you to drop everything just for her. She needs to realise that you're the baby's mum and she cannot control your lives by sulking and guilt tripping. Tell her a firm no if she doesn't expect it remind her that having a tantrum and going into a strop doesn't get her what she wants just like that behaviour won't work for your daughter when she's older either. If she wants to cut you off for not giving in to her demands let her you may get some peace from her

It's an unfortunate situation but you have to be firm now, because it will only get worse.

She's being a dick so don't feel too sorry for her. If managing her means keeping her at arms length then it does.

I know she's your mum, but would your husband be willing to help being firm with her? That bit of distance might help. Change things now, it will only get harder.

If she was actually thinking of your DD she would respect her nap times op, your mum is a selfish cow.
Just tell keep telling her no when it's not convenient and when she starts flapping her gums at you put the phone down, don't entertain any of her manipulative spiel.

My 16 month goes for a nap around 12pm for 2 hours. I make sure we are home by 11.30am. No excuses.

My family know the nap time. If they choose to come during that, they dont see DS.

Set some boundaries and stick to them. Otherwise its a rod for your own back.

I'm a dgm and dd1 is obsessed about her dd's nap times. I was never like that with my 4dc but it works for her and that's fine. I love spending time with dd1 whilst dgd is asleep. It's easier now as dgd is 19 months and only has one nap.

Give her your babies schedule, highlight when she can’t come as it will disrupt the routine your baby needs. The next time she wants to be a nuisance ask her why she wants to come when your baby is unavailable. Tell her to get used to it unless she intends to go and pull them out of school in a few years time.

Be firm. It's nap time now, so come later and child will be in a good mood and lots of fun.
We don't change nap time, or I get no sleep. Later is the best time.

You're an adult. You have your own child now. Sorry, your mom can't act like entitled spoiled baby brat.
Yes of course she loves her granddaughter and yes of course she wants to see her, fantastic.
But expecting you and your husband to drop absolutely any plans that you have in your busy life, at a moment's notice so that she can come whenever she says she's going to come, and if you don't allow it then she makes you feel guilty, hey, that's not right.
It's not right.
Would you do this to a friend?
Would you do this to a family member?
If anyone else but your mother did this to you, would you accept it?
Or would you find a way to set some boundaries for yourself, your child, your partner, and your life?
Boundaries are not mean, they are necessary.

Can you chat to her on a good day, rather than when you are being door stepped?

How am I?. I'm so tired. DD isn't sleeping well at the moment. Can I beg a favour? When you are popping in this week, can you check with me first. If we've been up all night, we might need to find another time, if she's cranky.

If it works, great extend it to a 2nd week, then another.

If it doesn't work, then try the tough approach.

It’s manipulative.

Let her strop, and bleat. Just let it go in one ear and out the other. I’d be telling her to grow up and stop being such a princess, and that I have neither the time or patience for her petulance, but I appreciate you may need to work up to that kind of conversation!

You don’t owe your mother anything op. Your baby, your terms.

If she comes and baby is napping she does not get to wake him up and play.
She can watch tv and wait for him to finish his nap.

But isn't she cruel messing with the schedule that you've decided is best for dc?

Let her sulk. She either fits in with when it's convenient for you or she doesn't get to see her grandchild. Is she abusive when she tries to guilt trip you? If so, mute her until she's ready to behave.

Do not mess with the nap!

It’s so important for the child’s sleep but also golden for the mum. 2 hours of peace to have a sit, eat, do some jobs, prep for dinner. You need to tell your mother why it’s so important.

Stop trying to avoid the to-do. Have the to-do, don't budge, don't let her see it annoys you, and when she's learnt it doesn't work, she'll knock it off. (Same deal with your DD, when she's a bit bigger). If tantrum-throwers see that it gets them their way, they keep doing it - why wouldn't they? Don't reward crap behaviour.

It's not fair on your baby. Enough reason to say no. Be less accommodating if your mother persists.

Say no, then ignore her. View it as practice for when your DD starts having tantrums.

Let her expect it.
Then just do what you want.

"No baby is napping now I won't wake her."

You "You need to leave now I am putting the baby down"
DM "But! Blah blah blah"
You "Sorry you should have come earlier or asked what my plans were. See you!"

"I don't know why you are behaving like this. All you have to call ahead and turn up when we agree. it's no hard"

To add, your mother sounds entitled and controlling, using poor behaviour and punishment to get you to do what she wants.
This isn't acceptable behaviour, have a look on the Stately Homes thread in Relationships about how to deal with people like this.