Step Sister seemingly not coping with baby or doesn't realise what's expected?

[Checkonetwo]

My step sister had a baby 4 months ago after wanting one for a very long time. She is 38.
Her partner did not want a baby and so she left him, only for him to change his mind so they got back together and she fell pregnant immediately.
Since the baby has been born, she keeps going out without him and my step mother is looking after him most days despite my step sister (SS) being on maternity leave. She also goes out atleast 3 evenings a week to have drinks with friends, leaving him with her partner. This has been happening since 2 weeks after his birth.

My Dad is exhausted as the baby is at their house everyday, including the odd overnight. But he won't say anything. He has a few health issues and needs some rest- he's 71. My step mother won't say no to her although she's exhausted too. They take care of my children twice a week after school so that I can work which I'm extremely grateful for (I'm a single mum) but I can see they're tired out and I feel guilty when I know they've had the baby all week. They say it's fine for them to look after my children for a few hours twice a week though and I don't expect them to provide a hot meal, they have sandwiches on these evenings.

However, they only have so much energy and my step sister is seemingly happy to zap it all from them. I have asked her if she's ok- thinking she must have PND but she keeps talking about how much she loves maternity leave. I think she's being honest- I think she's enjoying using the time for going out and having fun. Although, her partner doesn't seem very happy since the baby came along- I don't know if it's because she keeps leaving him with him in the evenings often when he's been to work. He did mention that when he gets home from work she's hardly ever in so I know he's getting home and cooking an evening meal for them for when she returns with the baby.

I'm a little shocked at the way she's behaving throughout maternity leave as she really, really wanted this baby. She's acting like she's enjoying her baby when I see her, but tbh, i think she's bored. She's always needed a lot of attention from her mother also. I'm concerned for my Dad overall, who has directly told me that he's exhausted by my step sister constantly being there/the baby being there. I've suggested he say something to her but he then shrugs it off and says it's fine.

I know it's not fine though- do I say something?

"If this isn’t nipped in the bud now you may find that they become too tired to look after your dc and that will affect the relationship that your dc have with their grandparents."

I worry about exactly this @FlamingoQueen they don't have this endless energy pot.

And there it is in a nutshell. You're worried about your childcare and nothing else.

CheckOneTwo I cant see why you are getting such a hard time here! 2 school aged children a couple of days /after School is nowhere near as tiring as a young baby.Your SS seems to have assumed shes got a Nanny! I understand you are worried about your parents ,but its not up to you to get involved.If they managed quite well with just your two .

What's going to happen when she falls pregnant again?!

Absolutely. Your SS is taking the piss or is unwell. It's hard for you because I'm the childcare isn't from your parents but from one stepparent and your dad which makes it harder to navigate.

Also, who is providing nappies and milk powder for the baby?

I'd agree with that too.

5yos esp after a full day in school are tired and happy to chill on the couch in front of the TV.
Old child probably does homework. And possibly plays with nearby kids.

I don't think it's comparable to a tiny baby, nappies, bottles, burps, wanting mum, esp the amount of time the Gran is being asked to babysit.

The Mum seems to be treating Mat leave like a big holiday. She needs to find some mum friends who are in the same boat.

In response to the person who posted about learning difficulties... it has crossed my mind. Her brother (my step brother) who is 10 years older (I barely see him) has high fuctioning autism. She definitely struggles with organisation and time management. I'd also go as far as to say that her mother's instinct isn't quite intune either (not that I'm saying this is autism related at all- more of a SS trait). She handed him over to me one day when he was crying and niggly and I could feel straight away that he had a temperature- it hadn't occured to her.

She will also allow my 5 year old to give him a bottle when he suffers with reflux and projectile vomiting (which led to weight loss in the beginning). Seems a bit irresponsible so I take the bottle and feed him myself or hand him back to SS.

She told me last week that the best part of maternity leave is having a year off work. She's intending on returning part-time- no idea why if she's enjoying all the time away from the baby that she's getting. She told me she was looking at nurseries but is hoping that my dad and step mum will have him atleast twice a week so that she can save on nursery fees.

The stepmother has been helping you with your kids, why she has to give an explanation of how much she is supporting her own blood grandchild ?! This is what mums are for

Some of the replies are ridiculous. If the OP had done a reverse no way would people be saying her and her sister are as bad as each other.

If people genuinely think caring for a baby day and night is easier than a five year old after school I think you must have had an angel for a baby, have rose tinted glasses or no experience.