Bagpuss does DD get DLA? If not, apply, if DD is awarded DD at least middle rate care you can apply for carer's allowance.
Muddling your LA will have a similar specialist teaching service to LIFT, just by another name. For your LA try googling advisory teaching service and your LA. If I've got the right LA they have a phone line parents can ring.
Runner sorry, I thought you may receive tax credits. DD does meet the criteria for medical needs tuition. The SENCO is talking nonsense. The LA may try to wriggle out of providing support but parents can challenge it. You can force the LA to provide education via Judicial Review. Often the mere works as it shows you are willing to enforce DD's rights.
Your LA like schools to refer, but there is no legal requirement for them to insist on this. Write to the LA, inform them DD has been too ill to attend school since x, school refuse to refer her for medical needs tuition and the LA have a statutory duty to provide education to those unable to attend school for medical reasons, including MH needs. Give them a deadline, 5 working days is adequate, and state if they fail to meet their statutory duty you will be forced to begin Judicial Review proceedings.
Zoo I'm not surprised you are stressed! You have so much on your plate to deal with on your own. Have you had a carer's assessment?
DD2 needs to realise she may be anxious, but she can not rule the house, especially since she isn't the only one with additional needs. It doesn't help anyone, least of all her, and DD3 and DS will become resentful if she dominates the house all the time. She has to help herself. Can you put in place screen limits? I know she is 17, but it won't be helping and she has shown she can not self regulate and as a result her behaviour is negatively effecting the rest of the household. Also, if she does have ASD she will be developmentally around 2/3rds of her chronological age.
One or two episodes is still a fair amount. It's not exclusion if DD2 is given the option to join in and refuses. Nor is it fair, or helpful, if you stop going out when DD2 has the choice to go with you or stay at home.
If allowed DS1 would take and take. We could give in to one thing, but there would always be something else.