bodymass       pregnant
  28.5            yes
  33.3            no
  23.4            yes
  26.6            no
  34.1            no
  26.4            yes
  45.6            no
  25.3            yes
  25.5            no
  24              yes

dfd<- data.frame(matrix(nrow = 10, ncol = 2))
dfd[,1]<- mother$bodymass
dfd[,2]<- mother$pregnant
header<- c('bodymass', 'pregnant')
colnames(dfd)<- header
dfd
chisq.test(dfd)

df <- read.table(text = "
bodymass       pregnant
28.5            yes
33.3            no
23.4            yes
26.6            no
34.1            no
26.4            yes
45.6            no
25.3            yes
25.5            no
24              yes", header = T, stringsAsFactors = F)

wilcox.test(bodymass ~ pregnant, data = df, alternative = "two.sided", paired = FALSE)

    Wilcoxon rank sum test

data:  bodymass by pregnant
W = 22, p-value = 0.05556
alternative hypothesis: true location shift is not equal to 0

library(ggbeeswarm)
ggplot(df, aes(pregnant, bodymass, color = pregnant)) + geom_boxplot() + geom_beeswarm()