Thanks so much for sharing more about each of your dc!

It sounds like it will work well to combine your 2 oldest daughters. I would do LHTH again with the higher level devotional with the 2 of them. I'd also add the Kindergarten Essentials Math from
Little Hearts for His Glory (LHFHG) for your 5 yo, as well as a handwriting program that works on the formation of letters. A Reason for Handwriting K or Italic A would be the choices HOD recommends, but you can use any handwriting you'd like. I'd also add the Fine Motor Skills books from LHFHG, which are "Do It Carefully" and "Finding the Answers." I'd wait on phonics. This will 'up' the level of LA/math in the areas your 5 yo is needing it, while still make it successful to combine the 2 girls. I've done "Little Hands to Heaven" too many times to count - with each of our 3 sons, and multiple, multiple times with 2-5 yo dc in our church during women's Bible studies. I never grew tired of it, nor did the dc who repeated it. I think just by switching the devotional and also the Bible (if you haven't used "The New Bible in Pictures for Little Eyes"). Personally, I'd get the LHFHG guide for the hands-on math lessons. If you do so, the following year when you get the rest of the LHFHG Economy Package, be sure to let HOD know you already got the LHFHG guide, and they'll verify your past order and credit back your savings of about $16.

I like this plan because it sets your 2 girls up nicely to be combined the entire way through. It also meets both of their individual needs in LA/math.
As far as laundry and cleaning, the ladies are right, it is tough with little ones underfoot! We had our dc begin helping at 5 yo with simple routine chores. I had them gather all of the bathroom garbage bags and consolidate them in 1 big tall kitchen garbage bag and take it out to the garage. Then, they put new bags in all the garbages. I also put away any sharp knives/dangerous things from the clean dishwasher, and had them unload the rest of the clean dishwasher, making piles on the counter, and sorting and putting away silverware. As they were able, they put the dishes/glasses in the cupboards. To do this, you have to be ok with occasional broken glasses and dishes.

I also had them fold washcloths and towels, and pair socks together from the laundry. They were responsible for bringing down and sorting their laundry on laundry days in the laundry sorter in our laundry room (whites, colors, towels). After meals, they 'swiffer' and 'shark' the kitchen floor, which entails going around the edge of the kitchen with a swiffer and using the cordless Shark to vacuum the kitchen floor (we have hardwood floors in the kitchen). Throughout the day, all dc are responsible for picking up their toys/games/DVDs/projects when they are finished with them. (Ongoing games and puzzles and building projects can be left out with my permission.

). Finally, at the end of the day, everyone can help with a "cleansweep," which is basically 'sweeping' through the house to pick up, clean up, bring up, put away anything that will make next morning's school day start without a mess.

In the morning, rooms must be picked up, beds made, and personal hygiene done (i.e. brush teeth, wash hands, clean clothes). All of these things our 5 yo dc could do, they felt proud to do it and contribute to the needs of the home, and I appreciated their help. The chores and responsibilities of our older dc change and increase as they get older, as I have a goal for them to leave our house fully able to care for their own house.
These are just a few ideas for your 5 yo. Training a child to do 1 chore well at a time routinely has helped things go smoothly. I usually train alongside them daily for several weeks. Then I check their work. I also give $1 allowance a week at this age that they may save/spend on anything they wish (even if it's not the best choice - this teaches much about money management.

).
As far as the house goes, at this stage, whatever you can do so you can wake up and start your day with a fairly clean house, as in 'clean' so you are not weighted down with a bunch of tasks in the morning that stress you out, that's the overall goal! For me, the things that bug me and weight me down are dirty dishes in the sink from yesterday, toys out everywhere from yesterday, garbages overflowing, piles of things places, etc. Hence the cleansweep the night before, and the morning chores I mentioned for your 5 yo.

You will know what drives you nuts and what you can let go! Get out of the way the 'drives you nuts stuff' right away, so you can get to enjoying your day!
For laundry, each of our dc has their own laundry basket in their bedroom. We do laundry 2 days a week. Everyone throws their laundry down the stairs (the boys like this - go figure), and then sorts it into the sorter. I used to do laundry as able throughout the day, putting clean laundry in baskets our on drying rack. We used to fold as a family then at night and put it all away. We usually do laundry Wed. and Sat., with towels on one of the days and bedding on the other as able. When I began working some afternoons, I hired a homeschool gal to watch the boys, and then she would fold the laundry on her days she came (I'd have it all clean and ready to fold, as she was there only a short amount of time). If you have a babysitter help out, this is a great thing for them to do as they watch dc too. I just had her set the folded clothes on each of the boys' beds, and then they put it away. This is what we still do now. I hope something here helps! But just know, a less than perfectly clean house with homeschooling getting done happily each day is SUCCESS in my eyes!

HTH!
In Christ,
Julie