Find Care & Housing
Will any of your other 7 children help out with the toddler? Not to be harsh but you are 70, and the child is 17 months? I could barely keep up with a baby / toddler when I was 30! Bless you for taking this on!  Kids today are a whole new thing,, they need to know computers in first grade, and kindergarden required knowledge that we learned in first grade! I can see where you need some help here.
Helpful Answer (1)
Reply to pamzimmrrt

So thank you all for your answers. I was not expecting such complete assumptions and advice but to explain We have 8 children, my oldest died of a fentanyl overdose in 2009. Her daughter is the oldest of four. She is the mother of my great grandson. Our youngest died in the womb at 8 months. My gran daughter is a product of a culture void of much morality and too much choice. She has signed over custody and guardianship to us. My mother is a very active and healthy 96 year old that was forced out of her condo by Hurricane Harvey on Houston. The home was a total loss so she moved to our home in NC. She will receive help from American veterans since my Dad was an enlisted man in the army during WW2 1942 - 1946. I hope That gives you the background you wanted. You can go to You Tube and type in Jew, Graham and Reagan and see a video about me.
Helpful Answer (0)
Reply to kbarun

Govt assistance for grandchild. 
Helpful Answer (1)
Reply to shad250

I’m assuming that the toddlers parents are MIA due to drug use &/or incarceration and so are beyond participation in care or financially, my answer is based on that..... in many ways a lot of what needs to happen for each is similar in that as a first start you need to legally have paperwork to establish your ability to oversee care of mom & grandkid..... for her it’s having a DPOA & for toddler some sort of release of their parental responsibility & over to you. So do you have these & if not you need an atty to draw these up.

As far as time & energy goes, Getting the toddler into a day program will be easier as there will be lots of options & price ranges. I’d do that so it gives you time to deal with your mom and finding a solution for mom’s care as she’s going to be more time consuming. If you are totally new to the world of “early childhood development” (aka programs before entering PreK) circa this millennium, it is NOT what you did when your kids were little 40 years ago. Kids now are expected to come into PreK already used to the classroom rhythm that a program provides.... like knowing “little voice”, using a cubby / a sit upon / 2 finger touch / white & interactive board use / play date & dump table etiquette etc. In my experience as a very much late in life mom is that kids nowadays that stayed at home with grannie or mom without being in a regular organized early childhood program are flummoxed and disadvantaged when they finally enter PreK or K. It’s already July so the lists for fall semester programs are getting filled so you may need to cast a wider net to find a program. I know for my city (New Orleans) where I’d suggest you start (Parenting Center at Children’s Hospital & the JCC’s). If your in a bigger city you may want to post that as lots of us on this site have city & state specific experience we can share.

For your mom, if you think she is medically “at need” for skilled care in a NH & has her medical chart that reflects this, I’d suggest you look to getting her into a NH and using her $ and assets to pay her care. Not your $ but hers. She goes in as private pay needing skilled nursing care. If she runs out of $ then she applies for Medicaid. So it needs to be a NH that is both private pay and Medicare and Medicaid beds. Most states Medicaid do NOT pay for AL, plus she’s 96, so having her move into a NH means she will not have to move & transition from AL to NH in a few months. If there has not been any commingling of her $ and yours then I think you should be able to do the paperwork needed for the financial  documentation required by Medicaid. If there has been gifting, or transferring of her money in large amounts to you or others, or your too overwhelmed then I’d suggest you just fold it and get an elder law atty to shepherd her Medicaid application. Her $ pays for the atty. You can’t do it all & if there’s glitches ahead let an atty deal with it from the start. Try to have a date night for yourself too.

Also I’m not trying to sound harsh about kids & drugs, but those in their 20’s & 30’s caught up in opioid or meth addictions and unable to properly parent their still dependent offspring so the grands end up parenting version 2.0 is the Shakespearian tragedy for our times. It’s not at all like dealing with the adversity of cancers or deployments as those have some sense of logic. There is no logic for a Fentanyl addict. 
Helpful Answer (8)
Reply to igloo572

Am I going to be sorry I asked...

And the little boy's parents and grandparents are... where? The reason I ask is not mere curiosity, it's also to gauge whether you expect this situation to be short-term, long-term, permanent or what.

What sort of help do you and your wife need? What are your mother's care needs, beyond general assistance?
Helpful Answer (5)
Reply to Countrymouse

Can your mother’s finances cover senior daycare?
Helpful Answer (2)
Reply to GAinPA