I reckon I might go shopping with her on Friday and pick out a new bedding set and side rail, then DH can see how he goes with her that night.
I have a side rail you can have as ds1 didn't need it - we put him in single beds when we did a road trip from Brisbane to cairns last year just after he turned 2 and we had no dramas (he's fallen out maybe 3 times in 18mths). Ds2 won't be needing it for awhile if at all.