Depending on the age of an older child, sometimes they anticipate what the younger one wants and gives it without the younger one asking. You need to observe if this may be happening. Unless your child is not speaking at all, encourage them to ask for things. The common words used are “use your words” They are used by therapists, daycare and kindy teachers. If you use the same ones you child has continuity and helps to prevent confusion for the child. I suggest you also have your child’s hearing checked. One common problem is known as “glue ear”. In some countries diagnosis is made by the age of 2 y.o. Speech and other therapies start at that age. A school friend was nanny to a child with ASD overseas. She took the child to speech and other therapies. Speech therapy can be a very slow process so the sooner it is started the better the outcome.

if your oldest child had so many issues i hope they are on the NDIA (or NDIS depending on what your local area calls it) If so they are fully funded to get a lot of services free to you.It is not only for the physically handicap(please excuse the term, it is for all that need the services a disabilitty can not alway be seen to the eye). My oldest child is on it then my youngest had symptoms like my oldest kid did, and from there it was easier to get him into the system as it is for early intervention.. If you get to it early enough with the right theropies it seems to be less severe than if left to deal with later… Fast foward two years with what has been provided my oldest kid he will be off the system in a year or two.. He has speech theropy every three weeks, pshycology once a month, and Occupational theropy every three weeks… Th Pshycoloist has described my son as a different kid to the one she meet two years ago and has developed in every way possible.. all going well she only wants to see him about another 6 to 10 times to ensure he is on the right track.. His speech theropist feels the same way.. he is no longer a selective mute.. The OT will need to see him for a while longer as he is behind where he sould be and not quite developing as he should in motor skills etc..
My youngest has he got treatment from a younger age about 2 years old he and i have the behaviour skills from the older child, i have managed to nip that in the bub before they happen..so no need to see the pshycologist. The speech theopist say he has now with 18 months of theropy where he should be and will not need much more of it.. But Again this child will need a couple of years of OT theropy to catch up to where he should be..
Believe in you self and put into practice all the things your other theropist have put into place for your older kid.. When you have a appointment for your older child ask them for some guidence and who you sould talk to for correct dignoses of our younger kid.. They are the proffessionals it is so much easier when the theropist you are seeing with one child takes on your other child as well.. Good luck

Children often imitate there siblings. I hope you receive respite services.

If you’re not sure, accessing a speech pathologist should be of help as they are trained in this speciality.

It’s hard to know, given your particular situation… Some second children to speak late (mine did), but it might be wise for you to get checked out.