After 7-10 days of hardening off they can be planted directly in soil. This, provided the garden soil is warm enough and there is no chance of a frost. A small greenhouse can be made from old storm windows and you leve the lid slightly open to allow heat to exit. Hardening off, firms up the plants leaves and stems so they resist early sunburn from direct sunlight. Also, air movement is essential. It may be wise to get herb plants a little later in the early season, so that they are more adapted to warmer outdoor temps. When planting, make sure you plant a slightly deeper than what they were in pots. Supports may be needed. Some herbs do not start or transplant well like dill, cilantro, and a few ohers that grow very tall. A light weight row cover is fine for reducing sun burn, light weight fabric will not protect from the very cold or frosts however. The row covers should not be in dirrect contact with the plants, so build them up like tents.

I feel for your daughter, as I have had fibromyalgia for 20+ years. When I am hardening off my plants, I use a kitchen cart to take them back and forth. I found it at a thrift store for just a few dollars. It has two levels, so there's room for quite a few plants. Unless she has to go up and down stairs, something similar might be of some help. Packing around flats or trays of plants can be excruciating and exhausting when you're supposed to be pacing yourself. I also use baskets with handles(also cheap at the thrift stores)for smaller plants.
After the last threat of frost, which can be May -June here, I usually take about a week for moving the plants(that I've started inside)in and out(to a shady spot), then up to another week of leaving them out, but adjusting them to more sun each day. I've noticed that many nurseries start selling plants well before they can be planted out. But of course, they either have started them in a greenhouse or had them shipped in from somewhere warmer. It's very frustrating if you don't have similar conditions to keep them in before planting time...and you know, you just HAVE to buy them when you see them!LOL! Hope some of this rambling helps.

I should add that I don't take the plants off the cart or out of the baskets, I just leave it all out so I'm not having to lift and bend so much. HTH

This helps a lot,i will pass this information on to her.Thank you.

noinwi,
She buys from a herb club,they have really nice herbs she tells me,so she does not want to go somewhere else,plus,her 11 year old son loves going with her,he always finds an herb he just HAS TO HAVE,ha ha
It is a pain,litruly,to move them back and forth,i just thought a row cover would make it a little easier.
Would this NOT work because the ground will not be warm enough,other wise, i would think as long as they are covered,they would be fine.
Thank you for your help.
Carol

Some herbs might work with a ground cover. But really tender ones like basil, dill, lovage, and any that would be treated as annuals should be kept inside and brought outside to harden as weather permits.

If her son has help he might like building a cold frame for his mother. There are kits that can be purchased or one can be built for the location. If they live in a area that has bulk trash pickup they may be able to find untreated boards for the frame. Old glass windows will work for the top. Metal storm windows can be lifted off but wooden storm windows should be attached with hinges and have something, stick etc, to hold the top open when it is warmer. A layer of leaves or yard trash could be placed on top for those times the temperature falls to zero.

I too buy from my local herb society and agree with your daughter that they have the best plants.

Thank you all, i really like the idea of a cold frame,yes,my hubby could make that for her,what a good idea, i will pass this by her to see what she thinks, :0)
Thank you,
Carol