I have a friend I've known for a few years. She used to be my neighbour before I moved house. We were always very friendly before but have become much closer in the last 3 years since she has had children. She's a bit younger than me, I'm 33, she's 25. None of her friends (all pals from school/college and similar age to her) have kids yet so she started getting in touch more when pregnant with her first as I was pregnant with my 3rd at the same time.
It's just lately I'm getting to the point with her where she is taking the piss out of me to be frank. We used to go to playgroup once a week / 2 weeks with the kids or do a little playdate at her house or mine.
She has recently gotten into a nasty habit of dropping her kids off at mine during our "playdate/group" time slot, saying she will be "an hour", and not come back ALL DAY - 9am until after 3pm. She has done this a few times this year and it seems to be becoming regular thing. Her girls are 9 months and 2.5 years, so need hands-on care obviously.
She is generally uncontactable during this time period, doesn't respond to texts, doesn't answer calls.. When she arrives to pick them up, she is always in a fluster and has a really elaborate excuse, usually involving rushing someone to hospital, or a car accident her "friend" was in, or an incredibly fluke, dramatic incident that's occured in town and she's had to stop to give a statement to police.......... seriously. Blatant OTT lies.
I spoke to her about it and said I've no issue babysitting her children if she's got things to do, wants to Xmas shop in peace, have her hair done, etc.. but she can't just be dropping them off as often as she has been and waltzing off all day with no notice. It's not fair. She agreed and apologised, but then texted later suggesting it's best to establish a routine, and for me to have them every Monday all day and Friday afternoons, PLUS every other Saturday night, overnight, so she can have a date night with her new boyfriend. 
I said she couldn't just book me in indefinitely, I'm not a childminder, and I might not always be free, PLUS I'm 8 months pregnant and not prepared to take on that sort of commitment, but happy to have them every so often. She found this to be extremely unreasonable after I had offered to have them, sulked for a couple of weeks and then seemed to forget about it and contacted me asking me to have them while she went for her Xmas works do. I hadn't heard from her at all for a fortnight and thought it was a bit cheeky, but happy to bury the hatchet.
She asked me to have her girls Friday evening and if I would drop them off at hers at "8ish". I agreed to have them but said I'd feel more comfortable just keeping them overnight (because I know she has a tendency to go a bit overboard with drink and didn't want to leave her in charge of 2 small children pissed up, plus they might be in bed by then). She accepted. All hunky dory.
Saturday came. She was predictably unresponsive. I took my three, plus her two to the park in the morning. We came back, had lunch. Little ones had naps. Still, she was uncontactable. Finally she texted me to say she was really hungover but she was getting up now and coming to get them. I offered to drop them off at hers (didn't want her driving if she was still over the limit). She accepted. I loaded all 5 kids into the car, drove to her house. Parked on drive, got her 2 out of car... Curtains shut, didn't answer the door, the phone, nothing... I ended up putting kiddies back in my car and going home. Evening came round and I received a long text from her mum saying that my friend was really poorly, probably had food poisoning from the buffet at work do (bollocks, she'll have been bladdered) and could I keep the kids another night. I was furious by this point but kept them - her mum doesn't have a good track record for looking after the kids (ie "nips" to the shops and leaves them all unattended in the house, drinks A LOT when supposedly babysitting, leaves them sitting in the car while she does her food shop.. all big no-no's in my book) so didn't want to encourage her fetching them.
My friend did not come back for her kids until Monday late morning. 
My husband was off work last week using up some holidays days so was at home. I left him with all of the kids and went onto the drive to "have a chat" with friend. She admitted to having spent the weekend in bed with new boyfriend. That's it. I pointed out how selfish, immature and bloody ridiculous it was... and she kicked off, shouting and pointing at me, ranting and raving, and in a nutshell, I'm a horrible cow for finding her behaviour unreasonable. I'm her friend and I'm making her feel guilty for having a good time. I should be encouraging her to be happy and enjoy life, not throwing it in her face. I'm jealous because she has a social life and I'm "just a mum". I'm sad and pathetic and if I was happy for her, I wouldn't try to make her feel bad.
.... for abandoning her two small children for 3 days 
She took the kids and went home in a temper. Messaged me today to say she's sorry for being horrible and know she has a temper. Sorry for taking advantage...... will I have them on Saturday night so her and boyfriend can go out for his brothers birthday 
Give me STRENGTH.
I've done nothing yet but on the verge of blocking her number and ignoring (I'm not on social media) and ending our friendship over this. I'm absolutely furious. AIBU and angry in the heat of the moment, or would you just cut her out of your life?